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How to repair Rheem FVIR water heater

FVIR troubleshooting guide
How to test if thermal device needs replacement
 Warning: With the inner door removed the FVIR, TRD, Defender Systems will be inactivated. If flammable
vapors are present, a fire or explosion may result causing property damage, personal injury or death.


AO Smith-


Bradford White-Boch-Lochinvar

Worst choice
Air intake on side
Uses glass vial trigger for overheating event
Arrestor screen located under combustion burner
Locate arrestor screen by removing burner
Clean arrestor screen with compressed air after removing burner
Company may send glass vial
Reset thermal reset on front of unit
New gas valve may be needed
Rheem Does NOT post service manuals
Best Choice in my opinion
Air intake on bottom
Arrestor screen stops acceleration of flames into room
Arrestor screen located under combustion burner
Locate arrestor screen on bottom of water heater
Set water heater on bricks
Clean arrestor screen with feather duster/ compressed air on bottom of heater
Reset thermal reset on front of unit
New gas valve may be needed
AOS Posts service manuals
Good choice
Air intake on side
Arrestor screen stops acceleration of flames into room
Arrestor screen located under combustion burner
Locate arrestor screen by removing burner
Clean arrestor screen with compressed air after removing burner
Reset thermal reset on front of unit
New gas valve may be needed
BW Posts service manuals

Fv system trips because of high heat.

1. Ignition of flammable fuel such as gasoline or paint thinner
2. Dirty air intake causes slowing of air flow up vent pipe, yet same amount of gas is being  burned.

Most brands can be repaired. Gas control valve might need to be replaced.
Prevent problems: air intake has to be kept clean, and ample air supply given to water heater.
Avoid dusty atmospheres, and flammable vapors 

Combustion chamber draws air from room
Bradford White has FVIR resistant:
What is FVIR or FV or TRD system:
Flammable vapor ignition retardation system

When water heater ignites, the heat caused by fire starts to move air upward. This action draws freah air up from air intake located under combustion chamber. The fresh air on Rheem water heaters enters from louvers located on side of tank near bottom.
In the case of power-vent water heaters, the blower motor draws fresh air into combustion chamber. With atmospherically-vented water heaters, where there is no draft inducing blower on top of unit, the metal vent pipe running up to the roof will create a natural draft upwards, just like a fireplace chimney naturally drafts upwards.
The vent pipe to outdoors creates natural draft upward that pulls freah air into combustion chamber.

If fresh air entering combustion chamber contains flammable vapors such as gasoline, then water heater burner ignites the gasoline vapor.
If unchecked, the ignition of gasoline vapor inside water heater will spread back out into surrounding room causing flashover or explosion that can kill you and burn down house.
With FVIR water heaters, this flashover event is retarded or stopped. So when vapor ignites inside combustion chamber, the FV system senses very high heat and immediately shuts off air supply to combustion chamber.
This prevents flashover or explosion inside room.
Insurance company property and casualty losses prompted FV safety mandate.
Each water heater manufacturer is responsible for developing FVIR system.
Rheem developed system with glass vial that breaks in event of FV event.


Exposure to flammable vapors, inadequate air supply, exposure to common household chemicals, clogged air intake, water heater dropped, vent pipe blocked, too many elbows in vent

Broken TRD TRD glass vial is broken
What to look for on Rheem, Ruud, Richmond, GE heaters
Verify TRD is activated (broken)

Rheem FVIR Rheem FVIR or TRD uses glass vial
When water heater experiences FV flammable vapor event, the glass vial breaks, causing spring door to snap closed cutting off air to combustion.

On Rheem/Ruud/Richmond/GE, if glass vial breaks, you need a new tank. Or Rheem or GE may send you part. Or, in case water heater is still under warranty, return heater to place of purchase for exchange.
Cause for FV event must be resolved before putting heater back into service.
Read manual and observe cautions, advisories, and maintenance shown in product manual.
FV water heaters are evolving rapidly. Information given here can be different than your specific model

FVIR shut off FVIR shuts off air supply
When glass vial breaks, the air is shut off to combustion chamber

FV event is caused when Flammable Vapors enter water heater. Tripped FV helps prevents flashover, fire and explosion inside house.

Larger image
Example illustration showing air intake and air shut off
Other water heaters have air intake located on bottom

Each model and brand water heater can vary as FVIR prevention evolves rapidly

Water heaters rated over 65,000 BTU do not have FV system. Tankless water heaters do not have FV system. Space heater, open fireplace, gas logs etc do not have flammable protection and each item listed above can ignite vapors and kill you if precautions are not taken.

Gas water heater burner Symptoms of  tripped FVIR
1) On Rheem, Ruud, Richmond, GE heaters, look for signs of shattered glass on combustion floor.

2) Symptons by type of gas control: With Robert-Shaw and White Rodgers gas control valve: If pilot light stays on without problems as long as gas valve is in PILOT position, but you then turn to ON position and main burner flutters and disappears within 30 seconds then good chance TRD is tripped.'
With digital-type Honeywell gas control and White Rodgers Intellivent gas controls, there are wires connecting combustion chamber and gas control that will shut off gas to burner and pilot. Pilot will not light. Burner will not light.

3) Caution: Same symptoms can also be bad gas control, low gas pressure, or clogged air intake.
Inspect if air shut-off baffle is tripped upward. Inspect for broken glass. Clean air intake. Avoid dusty atmospheres. If water heater brand is not shown on this page, consult manual for FV information.
Water heater manufacturers

4) If pilot will NOT light, and there is NO gas available, then ECO can be tripped. Check manual for ECO. Some ECO/TCOs are small button located on front of combustion chamber: this configuration is re-settable after overheating problem is repaired (clean combustion parts and air intake). Some ECOs are located inside gas control thermostat. ECO inside gas control is single-use, and gas control valve must be replaced. Consult manual. Follow maintenance schedule shown in manual for cleaning combustion parts. Test ECO

5) If pilot will not stay lit, then thermocouple might be bad. Test thermocouple.
Read: pilot will not stay lit


Telephone Rheem Solution 1: Call Rheem/ or GE or manufacturer of your tank:
Rheem, Richmond, Ruud, GE water heater: Gather information from label on side of tank, then contact Rheem and ask for glass vial, and other affected parts.
GE chat
Contact Rheem
Read product manual for advisories about warranty.
Other brands: Call Manufacturer and ask for replacement parts and repair steps, and read manual for advisories.
FVIR systems are rapidly evolving, and manufacturer will have current solution which might reqire water heater replacement.
Rheem warranty and extended warranty appear to be pro-rated and say: 'the limit of liability is reached when the repairs/replacement equal the replacement cost of 'like and kind' equipment during the term of the agreement.

Follow prevention steps shown below.
Water heater manufacturers

Return water heater Solution 2: Return water heater to box store where puurchased:
If you bought GE water heater at Home Depot, they will exchange for new heater

How to install gas water heater
Solution 3: Replace heater
Rheem, Richmond, Ruud, GE water heater must be replaced unless Rheem / GE can ship glass vial.
Other brands water heater also require replacement.
Install new heater and follow prevention steps below.

How to install gas water heater
How to recycle old water heater

Flame arrestor screen located under glass vial
Before repairs are made
Clean flame arrestor so air can enter combustion chamber.
Use air compressor and duster.
Clean air intake located on side -or- located bottom of heater. How to clean air intake
If air intake is located on bottom of water heater, then water heater has 3 legs, and screen on bottom of tank is could be difficult to clean without removing burner.
Clean burner and clean combustion chamber. How to clean combustion chamber
Remove all flammables and household chemicals from area.
Move water heater out of dusty, dirty environement, and set 18" off floor
Inspect vent pipe and check draft. Vent test

needle nose pliers
Off-code repair

Full image with words
Solution 4: Repair work-around: Bend part using pliers
 Warning:  NOT code. NOT recommended. VOIDS warranty. UNsafe since FV system is no longer operable.

How to repair TRD
How to repair Rheem FVIR: If you cannot buy the glass vile that holds spring loaded door. You can by-pass device by removing burner assembly and using needle nose pliers. Reach in and bend metal bracket that held glass vile. Bend it so it holds open spring loaded combustion air door. 
Next clean out the air intake, clean flame arrestor screen that filters incoming air, and follow prevention shown below. FVIR/TRD water heaters need plenty of clean air, and proper venting.
Your heater should now stay lit.

Solution 5: Repair work-around using ordinary fuse or nail
 Warning:  NOT code
Don't do this.
Insert cartridge type fuse (short variety) to replace glass vial

 This is not a game.
New heater costs a few hundred dollars. Hospitals, lost wages, lost careers, funerals, burned-down homes cost more.
I personally knew two fellows who were killed while laying floor tile in Chicago in 1978. They were using the old petroleum-based floor adhesive (now outlawed). Water heater ignited floor adhesive and conflagration killed both young men.
Recently, the local Lowes manager told me he had a friend who lost both legs. The fellow smelled gas. Instead of leaving the building and calling gas company, he removed front panel off water heater. The explosion and fire caused  life-altering injuries. His action by-passed the FVIR safety feature by removing front cover.

Gas control thermostatLarger image

Larger image
How to access FVIR/TRD.
Take photos of everything for easy re-assembly.

1) Remove wires as needed from Gas control valve and ECO located on combustion door

2) Disconnect Thermocouple, Manifold tube, and Pilot tube from bottom of Gas control. Notice these connections are not overtightened and do not require pipe sealant.

3) Gas controls vary. Manifold and pilot tubes on LP gas heater are reverse thread. Some thermocouples are reverse thread.

4) Burner door is held with 2-4 screws and may require replaceable gasket or sealant. Be careful with gasket so it can be reused.

5) Pull out burner assembly. It will fit under or into a slot.

6) Reassemble after repair. Do not overtighten connections. Thermocouple is usually finger-tight + 1/4 turn.

7) Use soapy water and check manifold and pilot tube connections for gas leak.
DO NOT remove or loosen the combustion door without turning off gas.

Gas water heater burner assembly
Larger image
Product manual has diagrams and advisories
How to remove burner

Example combustion cover removal for Bradford White

Troubleshoot gas water heater

Soot on gas burner
Soot on burner and/or top of water heater indicate insufficient air supply. This causes heat build-up and can trip FVIR

-Clean air intake.
-Clean combustion parts and chamber.
-Check gas pressure
-Inspect/ repair vent
Soot on water heater
Flame should be clear blue. Yellow flame indicates insuffucient air.

How to solder copper pipe
1) Do not store gasoline in open container.
How to prevent FVIR problems: (and ECO failure and other general water heater problems)
Caused by overheating inside combustion chamber
1) Do not store gasoline or flammables near water heater. Keep gasoline, kerosene in closed containers.
2) Avoid dusty atmospheres and give water heater adequate fresh air supply
3) Turn off water heater when using oil-paints, varnish, spray propellants, shellac, WD-40, thinners, lacquors, hair spray, gasoline, solvents, flammable cleaners, contact cement. Read product label to identify flammables.
4) Install water heater 18" off floor since gasoline vapors gather close to floor. Other flammable vapors do not gather close to floor.
5) Read product labels for flammability and advisories
6) Avoid storing or using chemicals in same room
7) Craft sprays and home project materials are flammable. Read labels.
8) Read manual and follow yearly maintenance schedule for cleaning air intake and combustion parts.
9) Make sure vent pipes are working and that combustion parts and top of water heater are not sooty.
10) Don't drop water heater

Remove flammables away from water heater

Be cautious
Explosion inside your home wastes precious fuel, and could burn down neighbor's garage.
Gas safety cans at Amazon

gas control knob
3) Turn off water heater burner and pilot when using flammables

Raise water heater 18" off floor
4) Set water heater 18" off ground

5) Read product labels for flammable warning: shellac, Kilz, lacquer, varnish, craft spray, floor paint, spray paint, solvents, accelerants, cleaners, etc
water heater air intake
6) Clean air intake regularly
FVIR cleaning
Dusty environments
2) Avoid dusty atmospheres and give water heater adequate fresh air supply

5) Read label for flammable warnings
Test water heater vent pipe 7) Check if flue has proper draft by lighting match

See if smoke drafts immediately upward.
The smoke should not linger. It should draw upwards quickly.
If vent does not have draft or if furnace vent is blowing out of water heater vent each time furnace turns on, then vent pipes must be repaired.

All gas appliances must vent out of house to avoid CO poisoning.
Read checking the draft
Water heater manual
8) Read manual for advisories, warranty and maintenance schedule.

Repurpose old water heater:
Recycle old water heater
Tempering tank
Solar water heater
drop water heater
9) Don't drop water heater.
TRD/FVIR will break

AO Smith FVIR water heater uses Cordite arrestor
Example 2011 manual
How to clean arrestor using vacuum and brush

Water heater cannot be put back into service if arresor is cracked.
Arrestor must be inspected,cleaned, and parts replaced as needed. Arrestor is not replaceable part.

AO Smith 

Same as American, State, Whirlpool, Reliance, GSW, John Wood
Water heater manufacturers

Image showing 2006 AO Smith FV design.
If FV event occurs, the arrestor screen is inspected for cracks. Then TCO is tested and replaced as needed. If screen is cracked, replace water heater. Otherwise, clean arrestor screen, remove flammable materials, and water heater is serviceable.

2006 design has Replaceable TCO shown
Page 18 manual

Larger image
Flame trap inspection

AO Smith

Image showing >2008 AO Smith FV design with mechanical gas control

2008-2010 design has resettable TCO located on front of water heater.
If FV event causes TCO to trip, it can be easily reset. And then arrestor screen is cleaned with brush and compressed air, and then inspected for cracks.
If arrestor screen is cracked, then replace water heater.
Using water heater with cracked arrestor screen will void warranty.

2010 AO Smith has Honeywell electronic gas control valve, with wiring changes for resettable TCO

Resettable TCO on front of combustion chamber
Larger image
Lighted inspection mirror
Flame trap inspection mirror at Amazon

Larger image
FVIR troubleshoot for Intellivent gas control valve
Resettable FVIR
Clear flammable vapors from area
Turn off power to water heater for 10 seconds
Within 10 seconds of restoring power, press both temperature adjust buttons simultaneously (blue and red triangles) until the green vacation LED begins to blink.
When Vacation begins to blink, replease temperature adjust buttons
Again, within 10 seconds, press both temperature adjust buttons simultaneously until the vacation LED is on steady without blinking ( 5 second delay)
Release temperature adjust buttons, the microprocessor will clear FVS lockout and normal operation will resume

AO Smith Effex water heater has resettable FVIR system
Same steps shown above are entered in control box located near top of heater.

Most water heaters need to be replaced 2012, but the manufacturers are working toward resettable FVIT.
And manufacturers have moved to conditional limited warranties that might require professional installation and yearly maintenance. Read the manual and specification sheet BEFORE buying. Call the manufacturer.

American high efficiency gas
AO Smith Effex
Larger image
Larger image 2
AO Smith Effex has resettable FVIR
Read review
Effex Service Manual

Same as Kenmore High efficiency, State high efficiency, and American high efficiency

Bradford White Defender
Bradford White has FVIR resistant water heater
1) Flame arrestor has large openings that reduce chance of dust and lint causing problem.
2) Likelihood of dust and lint clogging flame arrestor is reduced by the height of combustion air inlet located on side of tank
FVIR forum discussion
Bradford White Icon gas control valve features
Air intake
Large air intake reduces dust and lint problems
"In the case where trace amounts of flammable vapors are present in the air
flowing into the combustion chamber, the vapors are harmlessly ignited
by the burner / pilot flame. If flammable vapors are in sufficient quantity
to prevent normal combustion, the burner/pilot flame is shut down.

Should the flammable vapors continue to the burner, the flame arrestor
plate prevents the flames from traveling backwards and igniting vapors
outside of the combustion chamber. The calibrated, multipurpose thermal
switch recognizes this and shuts down the pilot and main burner. This
switch also deactivates the burner and pilot in the unlikely event of
restricted airflow caused by severe lint, dust or oil accumulation on the
arrestor plate."

Water heater must be replaced after flammable vapor incident/ read Pg34 service manual   Bradford White service manual
In event of overheating, or thermal event, the ECO trips and can be reset after cause of overheating is repaired

Bradford White flame arrestor

Designed to let air pass into combustion chamber.
But will 'prevent flames from traveling backwards through flame arrestor and outside water heater'
Read pdf

FVIR mandates were passed to reduce insurance casualty and property losses.

Many household appliances can cause flashover and explosion of hydrocarbon fuels
Tankless water heater
Hybrid electric water heater
Space heater
Gas logs
Faulty wiring

Tank-type gas water heaters are located in garages and storerooms where flammable vapor storage is probably more likely to happen. People are more likely to clean a paint brush using gasoline while in a garage, rather than in the kitchen or family room.
Water heater gas control valve Troubleshoot by type of GAS control valve
Troubleshoot by type of gas control valve

Remove gas valve
Leave house if you smell gas If you smell gas
Leave building immediately
Do not turn on light switch.
Do not stop to open windows
Call gas company
Gas is transparent but odorant is added so people can smell when gas is present. Illustration shows colored gas, but gas is transparent.

LP gas hugs the floor and can fill a basement.
Do not install LP gas water heater below grade (in basement).
Smell close to the floor when LP gas is used.

Natural gas rises.
You can easily smell natural gas while standing.

Install gas detector.

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