Range Oven Fires guidelines

OMB0029_2010_16_Range oven fires.pdf

Follow-UP Activities for Product-Related Injuries

Range Oven Fires guidelines

OMB: 3041-0029

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OMB Control Number 3041-0029

INVESTIGATION GUIDEILINE

Revised September 22, 1994
RANGE
(Excludes

Counter-top

AND

OVEN

FIRES

Units and Solid-Fuel

Fired Products)

Complete Attachment A for all fires. If fire resulted from cookingrelated activity, also fill out Attachment B. Attach to CPSC Form
182, Epidemiologic Investigation Report, along with copy of Fire
Incident Report.

I.

INTRODUCTION
A.

Background

Information

Based on data from the National Fire Incident Reporting System (NFIRS) and
the National Fire Protection Association, ranges/ovens were involved in the
following estimated residential fire losses in 1991:
93,100 fires
240 deaths
4,780 injuries
$394.6 million in property loss
Available data indicate that unattended cooking fires are a major cause of
range/oven fires. Other causes include failure of a variety of component
parts or features related to installation. It is believed that existing
technology is capable of reducing the fire hazard related to cooking
activities.
The purpose of these investigations is to provide details of the incidents to
help focus technical changes to these products to reduce the number of
fires, deaths and injuries.

Page

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6.

Product

Description

Definitions

and General

Description

-

Products
include any free-standing
range (that is, a combination
range/oven),
or a built-in and/or wall oven, or an installed cooking surface,
Plug-in and portable counter-top
units are not
except wood/coal-fired.
and hot plates.
Fires in
included; e.g., ovens, toaster ovens, microwaves,
exhaust hoods are included only if an integral part of the range.

-

Note

product

information

and illustrations

in Attachment

C.

C. Specific Items of Interest
If the incident involved cooking activities,
we are particularly
interested
in
learning the details, e.g., what was being cooked, over what time period,
(Fill out Data Record Sheet;Attachment
B in addition to
and heat setting.
Attachment
A.)
If the incident involved apparent arcing, gas leak, or other failure of a
component,
provide photographs
and a description
of the failure point.
Contact consumer immediately
to request that any failed components
not be
discarded,
e.g., gas valve, igniter, pilot burner, main burner, flexible
connector,
and heating element control.
Describe any previous problems with range;
malfunctions,
or difficulties
with use.
Include

diagrams

of controls

Please note that this
relevant information
investigation
should
has been anticipated

and settings

e.g.,

repairs,

perceived

if available.

is a guideline,
not a check list. Any
discovered
in the course of the
be included regardless of whether
it
here.

Page

2

of

31

INVESTIGA’l!ION GUIDELINE

D. Headquarters

Contacts

Extension 1275
Linda Smith, Project Manager, EPHA -- (301) 504-0470,
William Rowe, EPHA -- (301) 5040470,
Extension 1271
(301)
504-0608,
Extension 1356, Gas
Lawrence Hershman, EXCE -Ronald Jordan, ES--(301) 504-0508,
Extension 1295, Gas
Extension 1310, Electric
Mai Ngo, ESEE -- (301) 504-0494,
Renae Rauchschwalbe, EXCE -- (301) 504-0608,
Extension 1362, Electric
II. INSTRUCTIONS FOR COLLECTING SPECIFIC INFORMATION
(Data Record Sheets are attachments.)
A.

Synopsis

.

Describe the sequence of events that led to the incident. Describe the
incident including component failure or multiple failures (if known),
subsequent events, including contributing factors as appropriate, and details
of injuries.

For data retrieval from the computer, please make sure the
following key words are used in the synopsis as appropriate:
Cooking fire, surface element (halogen, radiant, solid,
conventional coil), bake elements, broil elements, plug,
thermostat, receptacle, electric, gas, gas lead, pilot light,
igniter, valve, gas control, flexible connector, pressure regulator,
gas regulator, explosion, LP-gas or natural gas.

B. Description of Incident Environment
Pre-Incident:
Include in this portion of the narrative a description of the unit
as installed, subsequent modifications (e.g., converted from LP-gas to natural
gas), and specific circumstances leading to the incident as follows:
l

- Describe product location, indicating cleanliness or neatness of use area,
and specifying items on adjacent counter-tops.
Describe any items that
were stored on or in the appliance.

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lNVESIlGATION

GUID-

Determine
if and where aluminum foil was used to
oven floor, under heating elements (electric)/surface

spills; e.g.,
burners (gas).

Measure clearance between
surface heating units and combustible
above and to the sides.
Indicate if wood cabinets.
Describe

details

of range

connection

to power

in

catch

items

or fuel supply.

Specify if the unit was wired directly into the circuit
armored cable or a cord and plug-in connection.

with

List the size, type, and manufacturer
of the overcurrent
(fuse or circuit breaker) and determine
whether device
off current during the incident.

conduit

or flexible

protection

functioned

device

to shut

Incident:
Describe in the narrative how the fire and any explosion happened.
State relevant facts and’ the source of any technical evaluations.
If the
incident involved apparent arcing, gas leak or other component
or
installation-related
failure, describe and photograph
in detail.
Determine
if there was an explosion or fire involving a gas leak and try to
specify the exact place where gas was escaping.
Photograph
relevant
component
parts, if possible, paying particular attention
to the area
between
the tank or gas line entrance,
the flexible connector
or rigid gas
If LP gas, determine
when tank was last filled, and
pipe, and the appliance.
any intervening
usage or sequence of events related to the incident.
Determine
if the regulator was frozen due to exposure to sleet or freezing
rain, over pressure on line, any problems with gas supply, e.g., turning on
burners.
Also make initial contact with the respondent
as soon as possible
to request that the gas valve, igniter, pilot burner, and main burner not be
Information of particular importance is: a) date of manudiscarded.

facture, b) year of purchase, c) location of gas leak, d) description of part
failure, e) identification of connector and coating materials, f) role of
movement of the connector, and g) presence of an ammonia atmosphere.
Determine
how produEt was being used at the time of the fire (e.g., for
cooking activities,
for heating home, or left on inadvertently).
If product
was being used for cooking, provide details of cooking activity as requested
on Attachment
6 along with any other relevant information.

Page

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of

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INVESIXGATION

GUIDELINE

If the fire started from cooking related activities, specify if the user left the
appliance unattended and for how long; the condition of the appliance
(e.g.,soiled from food spillage, clean surface, etc.); temperature setting
(e.g., high, medium); who discovered the fire and at what time; what was
being cooked and amount (e.g., four pieces of chicken in eight ounces of
corn oil); how it was being cooked and time period; and the size, type,
material and condition of pan (e.g., old and encrusted from food spillage,
clean pan, etc.); whether or not a family member was present just prior to
the fire and whether a power outage was involved.
If the fire appeared to involve the range or oven connections to the branch
circuit, provide as many details of the wiring and connection involved as
possible. Provide voltage, wire gauge, material of conductor and sheathing
(copy any markings available), and details of connection method including
grounding. Problems related to the use of aluminum conductors or damage
to power supply cords are of particular interest. Photograph connections
as appropriate to show failure point (e.g., terminal block or pigtail plug and
socket).
Describe any attempts to put out the fire (e.g., cover pan, use
extinguisher, etc.)
Post-incident:
-

Describe conditions that may have contributed to fire ignition or spread
(e.g., crowded or cluttered room, children playing, etc.).
Specify if the unit was repaired or replaced after the incident. Talk to the
repairman and gas company to determine cause of any component failure.
Specify estimated property damage, if any, including fire spread and dollar
loss.
Indicate if a detector (smoke, heat, or CO) was in dwelling, its location,
and whether it operated. If powered, but it did not operate even though
fire was big enough that it should have operated, indicate whether it was
battery operated or permanently wired, manufacturer, and model number.

Page

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1

INVESTIGATION

GUIDELINE

C. Description of Injured Person(s) and Product interaction
(Victim/Product Environment Interface)
- Describe accident scenario including all injuries and/or deaths sustained;
indicate if hospitalized, for how long, treatment, and prognosis.
- Indicate user’s age, sex, any competence reducing factors (e.g.,
impaired vision, physical handicaps, medication, narcotics, alcohol),
perception of hazard, user attitude, inability to read instructions, and how
victim was clothed if relevant, etc. Indicate any competence related
factors related to those injured and any other factors relevant to injury
occurrence.
- Specify activity and location of user (responsible for cooking) at the
time of the incident, and general activities of the household that day which
might affect use of the product. If cooking had been left unattended,
describe user’s activities during that period. .
-

Specify user’s experience with or knowledge of product, common
usage. Use diagrams to illustrate the use of the range/oven during the
incident. Indicate zrvho was closest to the unit at the time of the fire
and distance from the unit.

D. Description of Product
- List manufacturer’s name, brand name, and model/serial numbers.
Photograph all information from rating plate.
- Specify age of product, date of purchase, condition at time of purchase
(new, used, etc.).
- Specify size of product:

height, width, and depth.

- Specify who installed the range/oven,
man, homeowner, etc.

e.g., professional,

maintenance

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INVESTIGATION

GUlDmINE

- Indicate product history: previous problems including electric shocks,
gas supply and other repairs, modifications or alterations, etc. If repaired,
specify date, type, and who did the repairs (factory authorized repair
service; maintenance or handy man, homeowner, other). Describe routine
maintenance.
- Indicate whether the unit has an exhaust fan or hood, and if it is an
integral part of unit or separate item, and whether ducted. Advise if fan or
hood was filtered and free of grease or other materials, and whether
turned on at time of fire.
- If oven-related fire, indicate whether the oven has a continuous-clean
self-clean feature. Specify oven type, conventional or convection,
microwave, etc. and any other features.

or

- Show arrangement of surface heating units and all controls (both surface
and oven). Specify labeling on all controls. Photographs or diagrams are
extremelv imoortant.
- Specify type of controls, e.g., push and turn, push button, etc.
- Specify wattage rating and dimensions of surface heating elements
(burners)--usually stamped in area where element plugs in.
.

- Specify surface burner element types (e.i., halogen, radiant, solid,
conventional coil, gas burner module, etc.).
- Describe type of gas used, LP-gas or natural gas, and type of ignition
system.
- Determine if gas burner needed flame adjustment; i.e., a good flame is
clear/ blue and hardly visible in a well-lighted room, but a yellow-orange
flame indicates need for cleaning or adjustment.
- Describe any previous or current problems with gas supply, e.g., turning
on burners, over pressure, etc.
;’
- Describe condition of product before the fire.

Page

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INVESITGATION

GUIDELINEI

E. Product Safety Standards
CPSC does not have mandatory standards on electric or gas free-standing
ranges, or separately installed ovens or counter-top surfaces. Voluntary
standards for these appliances include the following:
_

Electric:

- Gas:
III.

UL 858 Standard for Household Electric Ranges

ANSI/A.G.A

221.1

Standard for Household Cooking Gas Appliances

INSTRUCTIONS FOR PHOTOGRAPHING
RELATED TO THE INVESTIGATION

AND/OR DIAGRAMMING

FACTORS

Photograph whole product and its environment.
Also, photograph and label
location of fire ignition (e.g., control, connector, element) and the rating
plate. Diagram and label surface elements and all control placements and
settings of the surface cooking or oven that are relevant to the incident. If
accessible, photograph date tag on the flexible connector, if relevant.
Try to photograph product with utensils and appliances in their positions at
the time of the incident.
IV.
.

INSTRUCTIONS FOR OBTAINING
THE INVESTIGATION

SAMPLES AND DOCUMENTS

RELATED TO

Stipulate whether the fire department was summoned and obtain a copy of
the incident report. Obtain copies of any insurance, utility, or repair reports,
installation instructions, maintenance records, and a summary of medical
records, if applicable.
If the fire resulted from component failure and component is available,
contact Mai Ngo, ESEE, (Electric), Ronald Jordan, ESEE, (Gas), or Linda
Smith, EPHA, to discuss sample collection for the Directorate for
Epidemiology.
Before collecting component samples for the Office of
Compliance and Enforcement, contact CECA.
L

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INVESTIGATION GUIDELINE

Attachment
DATA

RECORDING

A

SHEET FOR RANGE/OVEN

FIRES

Complete for all fires. To be attached to CPSC Form 182, Epidemiologic
Investigation
Also complete Attachment
B if
Report, along with a copy of the Fire Incident Report.
the fire was cooking-related,
either attended or unattended.

Incident

Task Number

A.

PRODUCT

IDENTIFICATION

Copy and photograph

1. Fuel:

0

Product

all information

0✔

Electric

If gas, indicate
2.

Date

in fire:

Range (combination

cooking surface and oven)

Installed

oven (separate)

Installed

cooking surface

Manufacturer:

4.

Model No.:

6.

Rating:

L7
✔ Other

Gas

type of gas being used:

involved

3.

on rating plate or tags:

a) Gas input rating (BTU’slhrJ:
b) Electrical

rating:

6.

Date manufactured

7.

Serial No.:
How

8.

Standards

Amps

(from rating plate):

long has consumer

Voluntary

Watts

Volts

had rangeloven?

Certification:

Page

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.

lNVESIlGATION

9.

Surface
a.

Cooking

Features/Controls:

Location:

Push button

Is there an indicator

light for the surface

Yes

If yes, are there individual

lights for each heating

light work for the heating

Yes

10.

Do any surface
specify which:

e.

If gas-fueled,

heating

specify
.

elements

Elements

Surface

Heating

Element Types:

Solid disk

a.

Location

b.

Diameter/size

c.

Power

d.

How

Radiant

heating

of involved

rating (stamped
element

Screw

temperature

sensor?

If yes,

non-electric):

Coiled,

plug-in

Quartz-halogen

unit that was involved

of surface

heating

or burners have an automatic

or Burners:

_

heating

unit involved?

ignition type (electric,

Heating

For surface

unit?

No

-

Surface

_

units?

No

Yes

d.

heating

No

-

Did the indicator

Touch

Push & Turn

Turn only

_

Other (specify)

Side

Back

Front

b. Type:
c.

GU-ID-

Coiled, hard-wired
lamp

Induction

cook-top

in the fire, indicate:

unit involved

in the fire (e.g., right rear):

element:

near connection):
was connected

terminations

to range:

(specify number

on involved

unit)

Plug-in tabs and receptacle
If tabs,

describe

shape (e.g., loop, flat blade):

Quick connect

terminals

Page 1O'of 31

INVESTIGATION

11.

Oven Features

(if oven was involved

Self-cleaning

GUIDEZINEI

in fire):
Continuous-cleaning

control

control

Timer control

Clock control
Broil element
Is there an indicator

Other

Rotisserie

Bake element
light for the oven?

No

Yes

-

(Complete

Attachment

B. INCIDENT
12.

C.

Type:

a

Cooking

Fire, either attended

or unattended

n

Gas leak (explain, for example:
leak in flexible connector or gas control valve, gas
line/pipe rupture, loose gas fitting, malfunctioning
pilot light, gas control valve, etc.)

0

Other Component

0

Connection

0

Used for heating

room

0

Left on following

power

0

Left on inadvertently

a

Other (specify;

Malfunction

B also)

(Specify)

Failure (specify)

13.

If gas-fueled,

14.

If yes, describe

outage

(nothing

e.g., potholder,

on range)
clothing

was burner flame abnormal?

ignition):
Yes

No

color and height of flame:

VICTIMW
15.

Number

deceased:

16.

Number

injured:

Page

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INVESITGATION

17.

Is there a detector
0

Yes

(smoke,
0

CO, heat1 present
U

No

GUIDELINE

in the dwelling7

Unknown

18.

If yes, specify

type:

19.

Detector

off (alarmed)?

20.

If no, do you know any reason why not; e.g., not powered,

21.

Before the fire, indicate

went

E. SOCIOECONOMJC
22.

Education
0

23.

24.

Q

No

Unknown

fire too small, etc?

the odor of gas was detected:

U

Less than high school

Rent

Completed

n

high school

home market

0

$15,000

- $34,999

a

$35,000

.

+

value:
0

Own

Provide general description, including all other relevant
the investigation form, CPSC Form 182.

factors

and information

Page

.

Some College

income:

LT $15,000

General Description:

0

level of head of household:

Approximate
U

whether

Yes

DATA:

Total household
17

LX

12 of

on

31

lNVESlTGATION

&JIDELlNE

Attachment
DATA

RECORDING

B

SHEET FOR COOKING-RELATED

(To be attached to CPSC Form 182, Epidemiologic
Attachment
A and copy of Fire Incident Report)

1.

Size of pan involved

2.

Comparison

in fire (bottom

of pan diameter

diameter

to heating

Investigation

in inches/capacity

unit diameter,

FIRES
Report,

along with

in quarts):

(if appropriate):

pan smaller
pan larger

*

pan same size
3.

Pan type,

4.

Burner/element

5.

Describe

food that was being cooked:

6.

Describe

cooking

7.

Type and amount

8.

Was the pan covered7

9.

What was burning when fire was discovered?

10.

material

(e.g., aluminum

saucepan),

control or oven temperature

process (sauteing,
of cooking

List all items that burned,

and condition:.

setting

at time of ignition:

boiling):

oil at time of fire:

or general extent

of flame damage:

.
11.

Length of time that food cooked prior to fire:

Page

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INVESTIGATION

12.

GUIDELINE

Who was doing the cooking?
Age

13.

User’s experience

(indicate

general history of use of appliance):

0

Several times a week

0

Other (Specify)

14.

Time of day fire started:

15.

Was anyone

in the kitchen

0

when

Once a week or less

ignition

0

Once a month

or less

occurred?

Who?
Indicate

where the nearest

16.

Was there an exhaust

17.

Was a reflector

__

Was the reflector

yes

No

Yes
under the surface

heating

element

at the time of the fire?

No

pan covered

-

were at the time of fire:

fan in operation?

pan (drip pan) located

Yes
18.

occupants

with anything

(to keep it clean)?

No

If yes, what?
19.
20.

In the past, had the consumer
Had the consumer

General Description:

experienced

turned the wrong
previous flare-ups

heating

element

on or off?

(gas)?

Provide general description, including all other relevant
the investigation
form, CPSC Form 182.

factors

and information

on

Page 14 of 31

_.

.--

Attachment
BACKGROUND

TECHNICAL

..

C
INFORMATION

I. Electric Section:
Electric Ranaes - General Information’
Counter

level ranges (left consist of a cook-top

level and an enclosed
the clearance

oven located beneath

between

with multiple

the cook-top.

the top of the cook-top’s

surface elements

The clearance

located at counter

“A” is the distance

cooking surface and the bottom

between

of an upper building

cabinet.
Some ranges (right) have a second oven located above the cook-top
commonly

referred to as eye-level

at eye-level

and are

ranges.

7

‘Provided

by Underwriters

Laboratories,

Inc.

Page

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31

-.

INWSI’IGATION

1.

Cook-too

Section

There are several types of electric
four coiled sheathed
inexpensive,

GUIDELINE

elements

arranged

range cook-tops.

in a rectangular

The most

pattern.

popular configuration

These elements

employs

are relatively

have relatively

higher power

and shorter heat up times than other types and have been on

the market for many years.

Most models

have removable,

by the user.

Power

ratings generally

are designed to be connected

range from less than 1200

to either 240

the back and can be lifted for cleaning.
immediately

beneath

the heating

plug-in heating elements

or 208

Volts.

Coiled heating

element

Watts to 2600

Most coiled element

element

generally

to help catch spilled food.

that can be replaced

Watts.

Most elements

cook-tops

are hinged at

include a drip bowl located

These drip bowls are removable

for

cleaning.
Another
elements

common

have become

cook-top

widely

element

available

popular in Europe for quite a long time.
the heating element
temperatures,
elements.
elements

imbedded

In order to have efficient

Solid disk elements

heat transfer

are constructed

and can automatically

are sealed to prevent

These elements

have electrical

Glass or ceramic,
gained additional

popularity.

opaque glass cooking

from the element

to the cooking

smooth

for ease of cleaning
Induction
ceramic cooking

using infrared

level.

utensil,

these

without

imbedded

coiled

dents or

in the iron disk

with a pot that has boiled dry,
Nearly all solid disk element

beneath the cook-top.

use radiant heating
radiation

cook-tops

elements

include one or more quartz-halogen

located

beneath

lamps.

elements

include a limiter thermostat

internal

begins to overheat.

a clear or

utensil.

Some

These quartz halogen

reduce the time needed to heat the cooking surface.

As with solid

to cut power to an
Glass cook-tops

are sealed

parts and wiring from spillage.

are similar to glass-ceramic

However,

for many years and have recently

to heat the glass and the cooking

if the glass cooking surface

and to protect

surface.

or reduce the power

These cook-tops

elements

element

the element

top units have been available

nearly all glass cook-top

heating

flat bottoms,

a “limiter” thermostat

spillage from accumulating

lamps heat very rapidly and sharply
disk elements,

contain

of

ratings similar to coiled elements.

surface,

of these radiant heating

portion

higher initial cost than the more traditional

caused by operating

turn off the element

with the active

This results in more stable cooking

must be used with pots and pans that have nearly perfectly
Most solid disk elements

These

only within the last 10 years, but have been

in a heavy cast iron plate or disk.

that can sense high disk temperatures

individual

in North America

longer heat up times and somewhat

other deformations.

cook-tops

type is the solid disk or cast iron element.

induction

cook-tops

cook-tops

in that they use a sealed glass or

heat the pot or pan using a magnetic

field rather

Page 16 of

31

INWSI’IGATiON

than a heating
electronics

element.

As a result, the cooking surface

to control the cooking temperature

Induction

cook-tops

generally

remains relatively

and are rather expensive.

user with the most control of cooking temperatures
available.

GUID-

from glass-ceramic

have lower power

user instructions
type controls

cook-tops

with glass-ceramic

A few

Induction

Induction

controls

vs. the predominant

cook-top

cook-tops

on

provide the
design
and

can usually be

in product

marking

use of conventional

units.

range cook-tops

cook-tops

ratings than other types of cook-tops

by the use of the word “Induction”

or by the use of electronic

They rely heavily

and are the most energy-efficient

must be used with iron or steel pots and pans to cook effectively.
distinguished

cool.

and

“knob”-

._

include

a grill or griddle.

These units are designed

to heat food

directly rather than using a pot or pan.
Some range cook-tops
type of heating
disk elements
receptacle

element.

2.

For example,

and a second module

arrangement

coiled element

.

that allows

module

Cook-too

units that can be removed and replaced

a range may be provided

consisting

of a grill.

module-all

range cook-top

elements

without

are provided

disturbing

are controlled

from Low to High, and are commonly

device does not sense or detect the temperature
power

is controlled

and back again - repeating
the “off” position.

The modules

consisting

of two solid

with a plug and

the appliance

wiring.

Controls

heat settings,

heating element

with one module

with a different

the user to remove the grill module and replace it with a griddle,

or glass cook-top

Most electric
continuous

are modular

of the heating

by switching

the heating

by cycling-type
called infinite
element

element

switches

switches.

or cooking

with
This type of

utensil.

from full power,

Instead,

the

to zero power,

the cycle over and over every few seconds until the user turns the control to

The control setting

determines

the amount

of On time and Off time during each

cycle.
A few coiled and solid disk cook-top
copper or brass capillary

tube, containing

located in the center of the heating
increases,

elements

a small amount

element.

determines

Range cook-top

the temperature
controls

the oven door), on a backguard

located

located

of the pot and the thermostat

element

elements,

A

disk
The

cycles on and off.

either in the front of the cook-top

behind the cook-top

switch.

to a small sensing disk

to send a hydraulic signal to the control.

at which the heating

are generally

by a thermostat-type

of fluid, is attached

As the temperature

the fluid inside the capillary tube expands

control setting

are controlled

or arranged

(just above

in a line to the left or

right side of the cook-top.

Page 17 of

31

All range cook-top
Conventional
cook-top

“knob”-type

controls
3.

controls

controls

necessitate

need two distinct

operations

to energize

require that the knob be pushed-in

the actuation

of two separate

buttons

a cook-top

prior to turning;
or touch

element.

electronic

pads.

Oven Section
The oven of an electric

holding food, two
baking heating

range consists primarily

or more sheathed

element

located

heating

beneath

elements

of an insulated

and a thermostat.

steel box, a door, racks for
A standard

the oven racks and a broiling heating

oven racks.

oven includes

element

located

a

above the

_
In the bake mode, heat in the form of infrared

broil) element

causes the temperature

radiation

from the bake (and sometimes

of the oven walls to increase.

The oven walls,

the

in turn, heat the air

and food inside the oven by conduction.
In the broil mode, food is cooked

by infrared

radiation

from the broil element

rather than by

hot air.
Oven bake elements
elements

are rated in the 3,000

are generally
to 3,600

Some ovens are provided
within the oven cavity
oven temperatures

compared

oven is raised to approximately
to water

a pyrolytic
1,000

surfaces

or self-cleaning

usually 400

‘micro”

in product

markings

located

broil

hot air is circulated
lower

for 2 - 3 hours, reducing
of ash.

inside the

any food residue left

During the self-cleaning

An inert catalytic

degrees Fahrenheit
cooking

to break down

coating

on the

as the oven is operated

or higher.

capability,

either in a separate

They can usually be identified

by the words

oven located

“Microwave”

or

on or near the oven controls.

Many oven doors are provided
inside the oven without

in which

cycle in which the temperature

cleaning feature.

Some oven designs include microwave
oven cavity.

Most

a fire or burn hazard.

ovens include a continuous

or in a common

Watts.

baking.

of the oven cavity causes food particles on the surfaces

at eye-level

and 2,600

food to be cooked faster and at slightly

vapor, carbon dioxide and a small amount

at higher baking temperatures,

Watts

cooking feature

degrees Fahrenheit

cycle the oven door is locked to prevent
A few

This allows

to conventional

2,000

range.

with a convection

by a fan or blower.

Many ovens feature

inside thsoven

Watt

rated between

with a window

and oven lamp to allow the user to view food

having to open the oven door.

c

Page 18 of 31

INVESIIGATION

GUIDEJJNE

II. Gas Section
A.

Gas Ranaes-General
Modem

Information’

gas ranges incorporate

pressure regulators

and automatic

controls for programmed

cooking,

automatic

requirement

National

is accomplished

such as thermostats,

gas valves.

In addition,

self-cleaning

oven controls

All of these ranges must be equipped
with current American

controls,

Standards

with automatic

Institute

by manufacturers

today’s

(ANSI)

pilots, gas

gas range may incorporate

specialized

or meat probes.
ignition of all burners in order to comply

standards

in different

automatic

ways,

for domestic

and further

gas ranges.

differs

This

in various sections

of the range.
For example,
tube ignition.

automatic

In this system,

ignition

of the top burner of a gas range is usually accomplished

a small metal tube called a flash tube conducts

air and gas from the burner cap to a standing
standing

pilot ignites this mixture

air-gas mixture

(Note:

pilot.

the standing

which then burns (“flashes

issuing from the flash tube injector port.

or slots to ignite the air-gas mixture

pilot.

throughout

system

The high voltage

the range by high tension

Another

means of automatic

the burner directly,
in an electronic

ignition

coil (glow coil) which

glow coils remain hot for a few seconds

employed

circuit which

in gas ranges is the electric

gives off sufficient

the

is usually

is distributed

The system

type of ignition system

glow coil.
employs

This

a small

heat to ignite the pilot gas when energized.
circuit is activated.

Some electric

after the pilot gas is ignited and then are shut off usually

Others may remain energized

Another

ports

leads.

The gas to the pilot is usually turned on at the same time the electrical

flame switch.

by carryover

thus eliminating

energy for providing the spark(s)

usually is used to light gas pilots for oven or broiler burners.

electric resistance

The

at the main burner ports.

The energy for the spark is developed

located at the rear of the range.

lit).

of

the flash tube to ignite the

This flame is carried upward

Spark ignition may be used to light the gas issuing’from
need for a standing

a fast burning mixture

pilot is manually

back”) through

by flash

by a

while the circuit is activated.

often found in the oven section of the range is the two stage gas

pilot.
Automatic

pilots incorporated

The bulb sensor is rigidly mounted,

American

in gas range ovens are usually of the mercury
since its position

vaporization

type.

with relation to the pilot flame must be maintained.
L

*Material on the operation of gas ranges has been used by permission of the copyright
Gas Association (A.G.A.) Catalog No. XH1275,
Printed in U.S.A., 5M3.84-2.5-2.0-577.

Page

holder,

19 of

31
.

I

INVESTIGA’IION GUIDELINE

Also, the complete

pilot assembly

the burner it is designed

(pilot burner and sensor) must be maintained

to light.

in a fixed relationship

to

For this reason most range oven and broiler burner pilots are mounted

directly on the burner.
Top burner range controls

In addition

infinite range of flame settings.
temperature
controls.

controls

are available.

They are the tower

bulb positioned

operated

gas valves which

to these basic top burner controls,

There are two basic types of top burner automatic

and the bypass type.

As the pan bottom

liquid exerts pressure

Both of these sense temperature

gas control valve,

top burner

temperature
by a liquid filled

with the bottom

of the

gets hot so does the sensor, and the liquid in it’expands.

This

top burner temperature

The expanding

acting to gradually

control,

as the cooking

In turn, the minimum

The minimum

cooking temperature

is limited by how small a bypass rate can be used with stable flames.
can be used, the lower will be the minimum
there is always

a flame

load (pan) heats up

fluid in the sensor bulb exerts an increasing

reduce gas flow to the burner.

used is referred to as the bypass rate.

the bypass system

an

in the gas valve to control gas flow to the burner.

In a bypass type of automatic
the sensor bulb also heats.

have virtually

automatic

in the center of the burner so that the bulb makes direct contact

vessel being heated.
expanding

are simply manually

temperature

indicated

pressure in the

gas rate which
which

is

can be attained

The smaller the bypass rate that

on the thermostat

control

present at the main burner ports in normal

dial.

With

cooking

operations.
The tower

..

operations

there is always

position.
maintain

burner system

The temperature

a flame on the tower

burner near the main burner.

During normal cooking

burner as long as the main burner gas valve is in the on

sensor in this case acts to cycle the main burner flames

the set temperature

maintained

uses a small tower

with this system

in the cooking
depends

load.

The minimum

load temperature

on the gas input rate of the tower

burner.

on and off to
which

can be

The tower

burner also

serves to reignite the gas at the main burner ports each time the main burner is cycled on.
The primary advantage
tower

system
1.

is that it permits

of the bypass system

lies in its simplicity.

The primary advantage

of the

control at a lower temperature.

Gas Oven Controls
Control

through the years.
temperature

of oven temperature

by automatic

means has been accomplished

in various ways

But in all cases an automatic

in the oven, and (2) an automatic

fuel to the oven burner.

These two

oven has (1) a temperature sensor that responds to
;
valve that responds to the sensor and controls the flow

devices can be combined

of

into one unit called an oven thermostat

Page 20 of 31

.

-

INVESTIGATION

valve.

The sensors used in most gas ovens today are the liquid or gas filled bulbs with capillary tubes.

Control of the flow
a.

of fuel can be accomplished

Modulating

temperature,
burner.

between

resorted to modulating

the limits set by maximum

This system

temperatures

ordinarily

as low as 250

would

provide,

to the control setting.

temperatures

250

Cycling

previously

Oven Control

electrical

stable flame on the oven

controls

stable flames

is called the bypass rate.

is that they provide a uniform

Their chief disadvantage

is their inability

temperature
to maintain

in the
oven

Systems

have been developed

oven temperature.

discussed.

gas rate used and minimum

F.

Several systems
off to maintain

the flow of fuel to obtain the desired

gas rate providing

of modulating

oven corresponding

b.

or cycling of the oven burner.

when used with proper burner and oven construction,

F. The minimum

The chief advantage

below

either by modulation

Oven Control Systems

Early gas control systems

One system

This all-gas two-stage

that use the method

incorporates

pilot system

of cycling the main burner on and

the two stage pilot valve which

has the advantage

has been

of not being affected

by

supply problems.
In another

switch

GUlDmINE

which

switches

cycling system,

controls

a liquid filled thermostat

an electrically

is a pilot flame switch.

operated

This switch

solenoid

low oven temperature

of the modulating

below

250

F.

2.

Controls

for Self-Cleanina

There are two
pyrolytic

system

continuous

different

simply

and cycling systems

oven temperatures

can be incorporated
valve modulates

to maintain

very

down to a low bypass

as low as 140 F.

Gas Ovens
systems

and the continuous

clean system

valve

extinguished.

In this case, the thermostat

rate and is then cycled on and off to maintain

Also, in series with the thermostat

gas valve.

opens the electric circuit to the oven burner solenoid

if the source of ignition for the oven burner becomes
A combination

bulb opens and closes an electrical

used in today‘s

clean system,

employs

modern

(sometimes

special catalytic

gas self-cleaning

ranges:

referred to as a catalytic

The

cleaner).

oven liners which are continually

The

self-cleaning

during the normal oven operation.
The pyrolytic
burn off any cooking
and satisfactorily

system

involves heating the oven cavity to wproximately

soil or spillovers.

For example,

a special door lock mechanism

of the oven door when the temperature
eliminated

Special controls are necessary

from the oven flue products

800

to complete

this function

must be incorporated

inside the oven cavity is greater than 675

F to 1,000

F.

to prevent

F to

safely
opening

Smoke must be

and they must be cooled before they are vented

to the kitchen.

Page

21 of

31

INVESTIGATION GUIDELDIE

The oven must be capable
temperature

sequence

of operation

First, the oven selector

switch

door is closed and locked into position
desired length of cleaning
The waist-high
supplied

for a pyrolytic

by an electric solenoid

time (usually between

When the oven cavity

any current

l-1/2

position.

lock.

is quite different

gas oven would

reaches a temperature
lock.

process is started.

the oven burner is automatically

of 675

F, a bimetal

switch

opens,

As a result, the oven door lock handle cannot

At the end of the cleaning

cycle, the clock timer acts to shut off gas

broiler burner and oven burner and the oven cools down.

lock prevents

of the oven door until temperature

opening

proceed as

The clock timer is then set for the

flow to the waist-high

3.

than the

At the same time the oven

and 2 hours), and the cleaning

After a few minutes,

flow to the electric solenoid

be moved to the unlocked

self-cleaning

is turned to the “clean” position.

broiler burner comes on first.

with gas.

preventing

F range which

range used in normal oven operations.
A typical

follows:

of being cycled in the 800 - 1,000

The electric solenoid

in the oven has dropped to below

675

F.

Broiler Burner Controls
There are two

“waist-high

broiler.”

Several rack positions

basic types of broilers found in domestic

The low broiler is located
are provided

fats to drain into the bottom
The gas controls

in the bottom

for the broiler pan.

gas ranges; the “low broiler” and the

of the range below the oven/broiler

The pan has small openings

to permit cooking

of the pan.
used with the low broiler are the same as the oven controls

burner is used for both broiling and baking operations.

There is one exception:

one additional

the oven/broiler

position

burner.

marked

“broil.”

In this position,

since the same

the oven thermostat

has

burner will remain lit or it may

cycle on and off or modulate.
The waist-high
additional

broiler is located

space is freed in the bottom

any broiler spattering
A separate
diverter-type

of the range for storage.

of the oven walls can be automatically
broiler burner and pilot are necessary

pilot valve.

simultaneously.

at the top of the oven cavity.

This valve is necessary

to prevent

With this arrangement

If the range is a self-cleaning

type then

self-cleaned.
in the waist-high
operation

broiler, along with a special

of both the oven and broiler valve

At a cold start this valve is open to the oven burner and closed to the waist-high

broiler

burner.
The sequence

for broiler operation

turned to the broil position.
glow coil.

This permits

is as folloks:

The combination

gas to flow to the broiler pilot where

When the broiler pilot sensor is heated

it causes the diverter

oven/broiler

thermostat

is

it can be ignited by a

valve to switch

from the

Page

22 of

31

INWSI’IGATION GUIDELINE

normally

open oven position to a closed oven position and to an open broiler position.

the broiler burner where

is turned to an oven position the broiler pilot gas is shut off and the

oven pilot gas is permitted

to flow.

valve assumes

open oven position

its normally

If an electric solenoid

As a result, the broiler pilot sensor is not heated,

valve system

on the oven or broiler burners.

flame switch
incorporates

to

it is ignited by the broiler pilot.

When the thermostat

to switch

Thus gas flows

sensor is used to detect
a flame switch,

while the two-stage

oven pilot is heating

is used, a simple electric thermostat

pilot flame and ignite the oven burner.
of infrequent

up its sensor.

switch

Usually in this type of system a standing

but because

so that the diverter

can be used

type oven pilot with a

The broiler pilot also

use has its pilot ignited by glow coil each time

the broiler is put into operation.
4.

Gas Pressure Resulators
The gas range, like other gas appliances

limits and will perform

safely and most efficiently

gas pressure regulator

is installed

is designed
within

to operate

this range.

in the gas range manifold

within

Therefore,

certain gas pressure
for purpose operation

to supply a constant

a

gas pressure to all of

the burner orifices.
On ranges, the regulator
near the top burner valves.
direction

properly.

In this position

of the gas flow through

regulators

is usually located just under the top section
it is easily reached for any adjustment

the regulator

must have the direction

and toward

of gas flow

is essential

for its proper operation.

clearly marked

needed.

the front
Correct

All design certified

on them so that they can be installed

.
The mounting

position

(upright,

on its side, up-side down,

Btu per hour

etc.) of some regulators

Btu per hour

Two top burners at

9,000

each

18,000

Two top burners at

12,000

each

24,000

Griddle burner

10,000

10,000

Low oven buyer

25,000

25,000

Elevated

13,000

13,000

Total

oven burner

is critical.

90,000

Page

23

of

31

INVESTIGATION GUID-

Capacity
For example,

is another

factor that must be considered

a range may consist

of the following

capacity

of at least 90,000

The operating
designed to operate
Domestic

Btuihr.

Btulhr.

gas ranges ordinarily

of about 4 to 6 inches water

are equipped

column.

Therefore,

for a range.

at the same time:

a regulator

with a maximum

must be selected.

pressure range of the regulator

in the pounds-to-pounds

a regulator

burners that could all be operated

The total input rating for this range is 90,000
regulation

when selecting

also must be considered.

range, while others regulate
with the inches-to-inches

Range regulators

Some regulators

in the inches-to-inches

type supplying

should be marked

P which

an outlet

indicates

are

range.
pressure

they are

designed to handle pilot gas flow.
5.

Manual

Valves

a. Shut-Off

Valves

A manual
positive shutoff
necessary

shut-off

valve should be used with a gas range to provide a me&s

of the range gas supply for servicing

if a burner valve had become

appliances

on the same supply line.

defective

and replacement

purposes.

and has to be replaced

On a range, the shut-off

Shutoff

without

valve is located

of complete
would

disturbing

be

other gas

ahead of all controls.

b. Top Burner Valves
Most range top burner valves are manual
controlled

top valves.

6.

Timers

The manual

The exception

would

be thermostatically

valves are usually of the plug and barrel type.

and Clock Controls

One useful accessory
may be digital or have sweeping
programmed

cooking

self-cleaning

sequence;

having settings

valves.

found on most gas ranges is the timer and clock control.
hands and can be used to:

such as start and stop cooking
(4) provide a timed

from one to sixty minutes.

(1) indicate time:

and cook and keep warm;

convenience

The clock

(2) control the oven during
(3) start and stop the

outlet; and (5) provide a minute

minder usually

At the end of the timed period, an audible sound is supplied

by a buzzer.

Page 24 of 31

lNVESITGATION

GUIDELINE

ELECTRK

_ ._

Page 26 of 31

_. . . .

.__

_

.

INVESITGATION

GUIDELINE

B. Flexible Connector
Flexible connectors,

generally

Some incidents

may result in fires and/or explosions.
end-fittings

and stress corrosion

leaks developed.
resulting

but to a lesser extent
Also, connectors

in stress corrosion

and window

cleaners,

ranges, have exhibited

bodies with either butted
with the lapped surfaces,

can be over-stressed

in the presence

and oven cleaners.

gas leakage which

have been traced to failure of soldered

of the brass tubes of the connectors.

were brazed or soldered to connector
butted surfaces,

used with free-standing

of ammonia

Prior to 1973,

or lapped surfaces.
corrosion occurred

during installation

or brazed

some end fittings
Particularly

with the

in the joint, and

or movement,

vapors from such products

as floor waxes,

floor

..

Page 25 of

31

INVESIIGATION

GUIDELINE

ELECTRIC

99

Fenture Index
I

Storage

Device

3 Anti-Tio

Label

Bake Unit
wiping

QQQQ

wx rll match h*e a11feaum.

Drawer

2 And-Tip

4

QQ

May

oven f&r.

(on some models)

I4 Surface

Unit On Light

IS Cooktoflift-Up
Cooktop
(on some models)

be

lifted gendy for
_

5 Broil Unit

I
1
I

16 Oven Vent
Located under right rear surfxe

unit.

17 Model and Serial Number Locztion
Located behind the range door or
behind the storaec dower.

6 Oven Door La&
use for Self-cleul only.
7 Surface

Units, Drip Pans

8 Surface

Unit Controls

,;

/

$j~~~;;ndo-,

19 Oven Shelf Supporu
Shelf positions for cooking are
suggested in tie Baking. Roasting
and Broiline sections.
-0

1 I Clock and Timer

(on some models)

12 Oven On Light

Latch Door Light
Preheated Light
Automdc Oven Light
(on some mod&)

Oven Shelf with Stop-lockc
(number may vary)

11 Rcmovnblc Oven Door with
Broil Stop Position
!&iIv removed for cleannine.
21

OvenDoor Gasket

I

13 Oven Temperature Knob

I

Page

27

I

of

31

INvEsLlGATION

GUIDELINE

GAS

Features of Your Range

Page 28 of 31

_

INVJBTIGATION

GUID-

GAS

Feature Index (Not all mcdeh have aI1 fe-.

Appevvlce

of features varies.)

I Backguard (on some models)
2 Surface Burners. Drip Pans (on some mode!s) and Gtaus
3 Oven Luno On/Off Switch (on some models)
4

Clock

5

OvenVent (locared

I

and Tuner (on some models)

6 BAKE/BROIL

on cwktop

I

on some models)

Switch (on some models)

7 OvenConrml

I

8 Surface Burner Controls

I

9 cooktop

10 Bmiler Pan and Rack
11 Oven Shelves (number of shelves vuia)
I?- Oven Shelf supports

13 +.ir ‘fen! in Oven Door (located at
14 Broiler Drawer or Stonqe
I5

top

of Oven Door)

I

D~~wvcr(dependioq on model)

Air InLake

1

16 Model and Serial Numbers @x.xcd oo front frame of range.
behind either Broiler Dnwer or Stonge Drawer)
17 Removable Oven Door
18 Anti-Tip Device (Lxxed

right rear ax bxbxn. See Insulladon Inrmrcriom.)

19 Oven Bottom
20

I

Oven InurIor Light (on some models)

-

.

.

Page

29

of

31

INVESTIGATION GUIDELINE

GAS

6a. ELECTRIC IGNlTlON SURFACE
BURNERS

OPERATIONOFSURFACE
BURNERS
ThlS range 1s equipped wth one of lhe lhree burner
F/pas shown below.

Operation of llectnc igniters should be checked after
range and supply line connecfors have been carefully
fi%cked for leaks and range has been connected :o
eltctnc power. To check for proper lighling. pusn !n
and turn a.surface burner knob to Ihe LITE positron.
You wtll hear the ignller sparkmg. The surface burner
should light when gas IS wadable to Ihe top burner.
Each burner should light -wthm four (4) seconds rn
normal operalion after air has been purgca from
supply lines. Visualfy check that burner has III. Once
the burner lights, knoo Would be rotated out of the
LllZ pos~tlon. There art separate lgmtron dewces for
each burner. Try each knob separately unbl all burner
valves have been checked.

UNEAR
FLOW

VALVE
III

11

THREE
POSlllON

VALVE

KNOB STYLES MAY VARY FRCM
PICTURED ABOVE.
VENTURI

SME

11

TWO
POSITION

VALVE

TnOSE

6b. STANDING PILOT SURFACE BURNERS
Afterrange and suppiy line tonnectlons have been
Carefully checked for leaks. purrje air from the
sys:em. The standing pilots must be lit immcdlateiy.
proceed as follow3:
1. Lilt mu” top. and locate top burner pllol
adjustment.
2. noId match over top ptlot until lit. After one pilot is
IA. ngnt the otflcr pIlot.
3. When both p~lors are lit. adjusl Ihe loo pllor
adiwtmenr unul the otlou are approxtimatq 1% fall
mth a very align; yellow tip.

I

SNAWN
STVLC

DUAL
smE

CHECK SURFACE BURNWS
To check for proper tightmg. push in and turn a
SU~~SZO
twnef knob to the UTE po%tmn. Each
burner should light wthm few (4) seconds in normal
oparatmn. Once the burner lights. knob should be
rotatedout of Ihe UTE poshon. Try each knob
scparatety unr~l all burner v&es have been checked

Page 30 of 31
.

INVESTIGATION

GUIDELINE

GAS

OPERATIONOF OVEN BURNERS
AND OVEN ADJUSTMENTS
9a. ELECTRIC IGNITION BURNERS
Operationof alcctrictgnitcnshould be checked aher
range and supply line connectors have been carefully
checked for leaks and range has been connected 10
alectric power.
The OVM~burner is CqUrppedwilh an elactric conuol
system as well as an llectnc oyen burner ignrter. If
your model is equpped mth a m&high
broil burner.
it will alao have an elecmc burner ~gnner. These
conuol systems requira no ad)usunent. When the
oven b set lo operate. a~rrent wll flow lo the igrwer.
It will ‘glowC similar lo a liih! bulb. When the ~gnrter
has reached a lemperature sti.z~cn! IO qmte gas, me
electncally coruolled oven vatve will open and flame
will appear al Ihe oven burner. There usa ttme lapse
from 30 to 60 seconds after the thermostat is turned
ON before the flame appears at the oven burner.
When the oven reaches the dial setting. the glomng
ignner WIII go off. The burner flame wll go ‘out’ in 20
IO 30 seconds aher the ignner goes ‘OFF’. To
maintain any given oven temperature this cycle wtll
continue as long as Ihe dial (or display) is se1 lo
operate.

.

After removing all packing materials and literature
from the oven:
1. Se1 oven 10 BAKE a: 330.. see QWNERS
GUlDe
for owratlna u1sm~d10~.
2. Wtihin 60 seconds (he oven burner should ignite.
Check for proper llama. and allow Ihe burner lo cycle
once. Rose1 con1rols to off.
3. If your model is caulpped wth a wars&high broiler,
sel oven lo BROIL. sea OWNER’S GUIDF for
operabng instructvans.
4. Wrthrn 60 Seconds Iha broil burner should Igmte.
Check for proper flame. Resel controls to off.

9b. STANDING PILOT OVEN BURNER
To

light the oven ~8101proceed as folkws:

Turn Ihe oven thermostat knob lo -Off. Remove
oven bottom. see step 10 for instructions on removing
Ihe oven bonom. Light Ihe oven prlol mth a match.
The oven prloc should bum mlh a stabb flam. after a
faw seconds operawn and should have a small flame
visrble only al lha openmg in lhe lop of the plot
-bly.

.

Page 31 of 31


File Typeapplication/pdf
File TitleAppendix 6 - Range and Oven Fires
SubjectComplete Attachment A for all fires. If fire resulted from cooking-related activity, also fill out Attachment B. Attach to CPSC
AuthorEXHR
File Modified2010-03-10
File Created1997-05-02

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