Troubleshooting Guide for Flame Guard and Flame Lock Water Heaters

411 plumb Flame Guard and Flame Lock Gas Water Heaters are made by American Water Heater Company and sold under the names American Proline, Whirlpool, Envirotemp, Mor-Flo, Powerflex, Premier Plus, US Craftmaster and possibly others. The Flame Guard and Flame Lock are names for FVIR (Flammable Vapor Ignition Resistant) Technology designed and manufactured by American Water Heaters. FVIR is a required safety design on gas water heaters that includes a sealed combustion chamber with a flame arresting barrier on the combustion air inlet and a device that detects a taller burner or pilot flame and shuts off the gas supply to the burner. If flammable vapors enter through the flame arresting barrier they may burn as excess fuel in the burner area but the flame cannot flash back through the flame arrestor to the source of the vapors preventing fire and explosion. Older styles of water heaters without the FVIR Technology could be an ignition source for flammable vapors, possibly causing and explosion and fire if a flammable liquid was spilled nearby.

Clogged Flame Arrestor on the Bottom of the Water Heater

Clogged Flame Arrestor on the Bottom of the Water Heater

Burner Enhancement Kit

Burner Enhancement Kit

There are a lot of possible problems with water heaters many of them quite generic which will not be covered in this trouble shooting guide. The focus will be on problems specific to the Flame Guard and Flame Lock design water heaters.

Early models of the Flame Guard and Flame Lock Water Heaters had a specially designed thermocouple that included a one time use thermal fuse that was designed to trip when a taller than normal flame occurred. These thermocouples were unusual in that they had a thermal fuse in addition to the usual flame detection function and they had a left handed thread to prevent the substitution of a regular thermocouple. The availability of these unique thermocouples was limited to a limited supply at Lowes and through American Water Heaters. The poor supply of replacement thermocouples with a fee for shipping and handling from American Water Heaters resulted in a Class Action Suit and Settlement where owners were supplied with a “Enhanced Burner Assembly” which included a new combustion chamber door, pilot/thermocouple assembly, burner assembly, and a thermocouple adapter. The models included in this suit have a round sight glass in the burner door and have serial numbers beginning with “FG” and “FL” and were manufactured between 2000 and 2006. Water heaters manufactured after 2006 have the “Enhanced Burner Assembly” already installed and have a serial number starting with a “B” The Class Action Settlement Period ended June 28, 2008.

Thermocouple Adapter

Thermocouple Adapter

The “Enhanced Burner Assembly” fixed the problem with the one time use thermocouple by using a resettable thermocouple which screwed into a thermocouple adapter. The thermocouple adapter screws into the left hand threads where the original thermally fused thermocouple screwed into the gas valve. Instead there is a reset button in the door of the burner assembly and 2 wires which connect to the thermocouple adapter.

FVIR Reset Button

FVIR Reset Button

The basic problem in most cases is a lack of combustion air caused by the screen of the air inlet on the bottom of the water heater. Frequent cleaning of this screen is required to avoid trouble. When the burner becomes starved for air the flame gets taller just like it would in an FVIR event and causes the sensor to trip. Some of the kits along the way also included a prefilter that wraps around the base of the water heater. If you have one of these keep it clean as well. Many people have luck making up a piece of pipe with an elbow on it to attach on the end of a vacuum cleaner hose to vacuum clean the screen under the water heater.

If cleaning the flame arrestor screen under the unit does not cure the problem there may be other problems relating to draft, insufficient combustion air, negative air pressure in the building or another problem in the unit that is best left to a licensed plumber.

If you have any questions or need additional help please leave a comment and I will reply.

Posted in How To Plumbing Tips, Water Heater Repairs Tagged with: , , , ,
127 comments on “Troubleshooting Guide for Flame Guard and Flame Lock Water Heaters
  1. JAMES says:

    I am having a problem with an American Proline natural gas water heater, The serial number starts with BFG.
    The pilot stays lit, but when the controller is moved from vacation mode to an actual heat setting, the burner will not flame up/ The thermocouple was changed out previously.

    • Redwood says:

      Hi James,
      Check that the thermocouple is properly placed in the pilot flame and the voltage is 12 millivolts or higher. If that is correct I’d suspect the gas valve to be bad and need replacement.

  2. Christine Oviedo says:

    Hello, my name is Christine I have an American Water Heater Company ProLine Flame Guard and it will not ignite. What should I do?

    Thank you,


    • Redwood says:

      Hi Christine,
      Can you send me more information such as the Model Number and specifics as to what will not light. Is it the pilot or the main burner which will not light? If it is the pilot, do you see a spark when you press the ignition button while looking through the viewing port at where the pilot should be? Are you correctly following the instructions to light the pilot?

  3. Troy Tindall says:

    I have a US Craftsmaster water heater with a Honeywell 6911131 control valve. My pilot will light but go out when I let go of the button and I never get any flashing lights. I can’t find a thermocouple to try first should I just replace the valve?

    • Redwood says:

      Hi Troy,
      Your gas valve is a new style which uses a “Thermopyle” to generate approximately 750 millivolts to power the electronics in the gas valve. Loss of this voltage signals the pilot being out and shuts off the gas valve for safety similar to the old thermocouples did. It takes about 90 seconds in proper flame contact for the thermopyle to start generating the required voltage. You may be releasing the pilot lighting button too soon or, the thermopyle may not be properly positioned in the flame or, the thermopyle may be defective. If you use a multimeter to measure for 750 millivolts across the thermopyle terminals after 90 seconds and you do not have the required voltage it is a thermopyle problem, if you have the right voltage it is a gas valve problem.

  4. Cherlyn Lee says:

    Hi. I have been struggling to figure out this situation. Is there a 2nd enhancement kit? The waterheater I have the serial number starts with BFG. My thermocoupler is threaded right handed. The thermocoupler adapter I have in my kit is left handed threaded. Do I have the wrong kit?

  5. Rowan says:

    Hi there! I am renting a house with an American Proline Flame Guard water heater, and I’m having some issues. The pilot went out yesterday and now that I’ve relit it, the red status light is blinking four times rapidly. It says that means that it’s overheated, but now there’s no hot water at all (even with the pilot lit) and the status light is blinking four times. I’ve tried to reset it multiple times, and there’s still no hot water. Is there a way for me to fix this? I’m not a very handy person, and I don’t have a lot of money to spend on replacement parts. Any fix you can think of would be appreciated. Thanks. 🙂

    • Redwood says:

      Hi Rowan,
      You really need to call your landlord on this problem. It is their plumbing and their responsibility to repair it. You could incur liabilities for touching the plumbing beyond normal usage.

  6. Mike says:

    Hi, I have one of these horrible American Water Heater company/Whirlpool water Heaters that are of the FG model. I already received the replacement manifold about 4 years ago and have now just started having problems again. I noticed the pilot light was out so I went to relight it and it lit right up. The next morning, it was out again. Was able to relight again, but next morning it was out again and this time wasn’t able to relight. Replaced the thermocouple and still didn’t stay lit. Replaced the thermocouple again….still had the same problem. I cleaned the burner with a wire brush and made sure nothing was blocking the pilot orfice.
    I do not not what to do next. I admit I did not clean out the bottom filter, and I will surely do that next. But what would you suggest if that doesn’t fix the problem? Thanks for your help.

    • Redwood says:

      Hi Mike,
      I’d always start with making sure the bottom “Filter” or, flame arrestor is clean so the air flow into the burner chamber is good. However, typically the button on the thermal switch would trip if the flame arrestor was blocked. I’d make sure the Thermocouple is properly positioned in the flame and the pilot flame is good, then test the thermocouple to make sure the voltage from the thermocouple is correct.

      Flameguard Thermocouple

      You can download a copy of of the Flame Guard FVIR Troubleshooting Guide by Clicking Here, and it shows how to test the thermocouple for the 12 millivolts minimum required to hold open the gas valve. If the voltage from the thermocouple is good I’m afraid that the next step would be to replace the gas valve, which is getting a little pricey.

      On the bright side you have an aging Flame Guard Water Heater and the day is approaching where it will need replacing. Have you seen the article here on 411plumb “Bradford White Defender FVIR System Water Heater Review?”

      Hopefully you have a few less hassles with your next water heater,

  7. vinnie says:

    Had a power outage an now status light will not come on. no status light then can’t start procedure to light up water heater.

  8. Josh says:

    Just wondering if you can help me. My dog somehow chewed off just my thermal switch on my us craftmaster water heater, just wondering If I can just replace that little thermal switch or do I have to buy a new assembly? Thanks

  9. don says:

    i have a us craftmaster lpg water heater and after i light it the light flashes 4 times meaning tempature exceded. the pilot light is really big and it does not fire up the burner.

    • Redwood says:

      Hi Don,
      I would recommend calling a plumber to look at your water heater especially if you have already cleaned the flame arrestor. While a clogged flame arrestor and the associated bad draft may cause the flame to bloat, I think your problem may be more serious, especially if you are getting the overheating code flashing.

      The problem may be excessive gas pressure or, the orifice size may be too large, a plumber would have the correct test instruments to diagnose the problem.

      Hope this helps,

  10. Brian says:

    I bought a house 2 months ago. I began having problems with the pilot light not staying lit yesterday. Thanks for your site and the information you have provided. I called the company this morning and he said that the previous owner of the house had already ordered the kit (and we are assuming had it installed) and that I should only need to replace the thermocouple. I asked for a part number. He gave it but said that if the kit has been installed that it’s no longer a left-hand threaded deal and I could use any 24 inch thermocouple. Is this accurate? From what I had read here and elsewhere, I don’t remember anything saying that you could use a regular thermocouple after the replacement kit. Please advise. Thanks!

    • Redwood says:

      Hi Brian,
      If the “Burner Enhancement Kit” has been installed you will see that there is a thermal reset button on the sealed combustion chamber door and the thermocouple will have a regular thread rather than a reverse thread. There is an thermocouple adapter that was part of the kit which takes the thermal fuse out of the thermocouple and converts the thread direction as well as taking out the wiring for the thermal reset button to be used. If you have the thermal reset button, and wires from it connecting to the adapter at the gas valve a conventional thermocouple can be used.
      Hope this helps,

  11. Chuuter says:

    Thanks for this article – you are a Godsend! I feel like I at least am headed in the right direction. I have been without hot water since coming back from NY state where I was visiting my family. I got back here the 29th of December. I have a PremierPlus Water Heater that starts with an FG in the serial number. My house was finished and I closed in January of 2006 – probably before the suit was finished.

    I have replaced thermocouples before in the other homes that I have had. It has never been much of a hassle. This one is a nightmare! I have been looking all over the place and reading everything trying to find out why I cannot get a thermocouple for this unit. Should the builder have had this fixed? A bunch of my neighbors in this development all have the same heater model.

    The builder is Sunrise Homes down here in Hillsborough County. Should I try to get the builder to replace this or do I not have a right to ask this since there was a class action suit? If I have no such recourse, what is the cheapest way to get out of this mess? I never thought that a simple thermocouple would turn out to be such a hassle.

    These cold showers are getting old! Can I ask the HOA to put a link to your article on this developments website? If I can prevent everyone else from going through what I am going through this all will be worth it.

    Any help or advice that you could give me would be highly appreciated.

    • Redwood says:

      Hi Chuuter,
      The limitations of the class action lawsuit only includes the water heater manufacturer providing the “Burner Enhancement Kit” without any provisions for installation of the kit with instructions that say, “It is so easy a cave man can do it.” That said, basically the job entails disconnecting the gas supply to the pilot and main burner, disconnecting the thermocouple, and removing all of the screws from the sealed burner chamber door. Once that is accomplished, the entire burner assembly is removed from the water heater. The flame arrestor should then have compressed air blown through it from inside the burner chamber to clean it and allow enough air to flow into the burner chamber. At a minimum the flame arrestor should be cleaned from below with a brush and some attachment on a vacuum cleaner which is slim and curves upward allowing you to vacuum off the accumulated dust and lint on the flame arrestor. Then you would have to install the enhanced burner kit and put all the screws back in while hooking up the gas and thermocouple connections.

      I hardly think that this is a job which should have been left to the consumer, with them being told, “It is so easy a cave man can do it.” but alas when there is a class action lawsuit it never really is a “Win” for the consumer, it all too often is a “Win” for the manufacturer of the defective product.

      What I would recommend is that since you are without hot water that you immediately call State Industries the maker of Premier Water Heaters at 1-800-365-8170 and make arrangements to have them send the “Burner Enhancement Kit” to you, so that you can have hot water again. Then you should get with your HOA and see if you can interest them in helping all of the other home owners in your HOA with finding how many of them have water heaters affected with this defect then perhaps having a plumbing company come in and repair all of them as a group purchase to obtain better pricing. If a company comes in and does the work going from home to home making the repair they can do the work more efficiently and pass the savings on to the HOA as a group.

      You are certainly welcome to link my website on the HOA association website to provide this information to the other homeowners and help them out with their water heater problems.

      I hope this helps,

  12. bob says:

    I have a gas 50k btu american water heater, powerflex that i recently purchased. It worked fine for about 2 weeks, now it won’t ignite.
    Received the lockout code when it failed.
    The powervent runs, the thermocoupler glows, I hear it switch to push gas through, but nothing happens, no flame, nothing.
    I don’t see a screen (flame arrestor) in the bottom of the water heater.
    Lockout code says,
    1. Gas supply is off or too low to operate.
    2. Hot surface ignitor not positioned correctly.
    3. Low voltage to the water heater.
    4. Electric ploarity to unit is incorrect – test and correct.

    I’ve pretty much ruled out 1, 3, and 4.
    How do I know if the hot surface ignitor is positioned correctly?

    • Redwood says:

      Hi Bob,
      It’s hard to say for sure without being there. Even your ruling out can be suspect, without knowing what you did to rule them out. Did you actually measure the gas pressure? Is it the gas valve you hear clicking? Do you hear gas rushing to the burner? Is gas going to the burner? I’d suggest calling American Water Heater’s Help Line as you’ll need to call them anyway for warranty parts if needed anyhow. They are the ones you’ll have to jump through the hoops for.

      I hope this helps you get hot water again,

  13. Kevin says:

    Hi Redwood,
    Interesting situation. Whirlpool BFG 40 gal propane water heater. Light pilot, thermocouple holds and pilot stays lit. Turn gas nob, and burner turns on. Next morning pilot is out causing to re-light. This has been going on for a few days. Taking a shower requires a trip to the water heater.

    Thought there was a bad draft, but everything checked out and was drawing correctly (and has in the past). Changed thermocouple thinking it may be getting weak after a while. Pilot flame was large, blue, engulfing thermo end, and holding as was before. Still same results – extinguished after one recovery cycle. No vapors or distillates in the area, and thinking it could be a combustion issue, I opened the inner door slightly to allow air in and a clearer look at the burner/pilot. Even recorded a video so I can view time-lapse. Pilot lights and stays lit initially, burner ignites as expected, thermostat reaches temperature, burner shuts off, pilot remains lit for almost 1 minute. Video recorded a slight “twang” similar to a guitar string (not the magnet when thermostat reaches temperature), and the pilot cuts out. Subsequent attempts to re-light pilot fails unless you wait a spell. Thermal switch seems like it kicked in.

    However, there are:

    • a) no flammable vapors
    • b) combustion chamber is open to air now so should not be restricted (will check flame-guard vent anyway)
    • c) thermostat remains on until thermostat has reached temp AND THEN pilot goes out a minute later, not all at once as I would expect if combustion chamber overheated.
    • d) Thermostat for Water temp is set to 120-130 only.

    Water heater is located in well ventilated area and same reaction is obtained whether flame door is on secure or loosened enough to view flames of burner/pilot. Before taking video, was thinking the burner cutting out and having one last backdraft (as gas gets cut from thermostat control) was blowing pilot out (sim to the effect you get w/ an old gas grill), but video proves otherwise. Any thoughts as to what could be happening here?

    • Redwood says:

      Hi Kevin,
      The draft test was an excellent starting point. Did you perform that test while any equipment that moves air in the home was operating? furnaces, dryers, exhaust fans are all possibilities, and the open door does kind of rule out the flame arrestor as the culprit at least while it is open.

      I’d look to making sure the gas pressure is adequate again while the water heater is operating and other gas appliances are also on and operating. If the gas pressure is good then I’d say it is the gas valve that is causing the problem.

      I’ll E-mail you a Troubleshooting Chart PDF File.

      Hope this helps,

  14. Chris Grier says:

    I called whirlpool to get the “Enhanced Burner Kit” but since my water heater was made in 2002(out of warranty) they are charging me $40 and another $20 to overnight it 🙁

    • Redwood says:

      Hi Chris,
      Sorry to hear that you have to pay for their screw up, unfortunately Class Action Lawsuits do have limitations and eventually the customer’s rights for compensation expire. With an 11 year old water heater approaching the end of its expected service life I’d consider replacement as an option before spending too much money on repairs. With that I’ll give you a strong recommendation for a Bradford White water heater.

  15. Dan in NJ says:

    Great website and need some help please!

    I have Whirlpool and the pilot light goes on but the main burner just wont kick start – I shut the gas off, wait 20 seconds and hold the trip/reset button on the FVIR and that usually works. However, the last few days it hasn’t ignited. I’m trying everything here, do I need a hole new burner kit?

    • Redwood says:

      Hi Dan,
      The “Enhanced Burner Kit” changed the “One Time Thermal Fuse” in the thermocouple to the FVIR button switch. You have the newer version in your water heater.

      Is the pilot light remaining lit but the main burner doesn’t come on or, is the pilot light going out?


  16. Bob says:


    I also have a whirl pool water heater and my heater has a cast iron burner, I noticed that I can remove the thermo
    adapter and thermo switch from the new burner kit and install it on my old cast iron one, by drilling a hole
    for the switch. I believe it should work, also replacing the thermo coupler with a universal one. will this work ?

    • Redwood says:

      Hi Bob,
      Install the complete enhanced burner kit without modification. The thermocouple adapter also has to be used as the old style thermocouple with the thermal fuse is left hand thread.

      • Bob says:

        Hi Redwood

        Well I noticed that the new unit has a right hand thread thermocouple, which I transfered to the cast iron burner and I used the thermocouple adapter, the only difference is the thermoswitch. I only have to transfer this to my cast iron fron face plate to exactly position like the new one. The only difference is that now you have a heavy duty cast iron unit to the cheap thin sheet metal one. I have finished the transfer but I have not yet drilled the hole to transfer the thermoswitch. That is the only piece I need to install. They are both identical except one is cast iron and the other cheap thin metal but with the thermal switch and thermocouple adapter to fit the right hand thread thermocouple.

        • Redwood says:

          Hi Bob,
          Sorry for legal and liability reasons I cannot recommend or, endorse altering the factory supplied parts of a gas appliance.

  17. Mubbin says:

    Hello Redwood,

    I had a john wood water installed in 2009(model JW40S34FV)which started giving problems in 2012 – pilot light would go off.

    A technician took apart the burner unit which was covered with some brown corrosive liquid. John Wood subsequently replaced the burner unit in 2012.

    Apparently, over the last few weeks (May/Jun. 2013), the pilot light keep going off every second day – I turn on the pilot light and same problem.

    I’m now in a dilemma as I’m not sure whether to get a new water heater or get this one “fixed” John Wood is no longer interested in helping out any further.

    Thanks very much

    • Redwood says:

      Hi Mubbin,
      It sounds like the flue might be be improperly installed and condensate is coming back down on the burner and corroding it.

  18. Matt says:


    I need some feedback. Just installed the new l.p. manifold kit with the thermal reset switch on US Craftsmaster. Everything works as it should however after 2 minutes of running the flame starts to stutter and the burner glows red. Water heater continues to operate fine but I can slightly smell gas. Called the company and they had no suggestions. My old manifold had a cast iron burner this one is sheet metal. Can someone verify that the sheet metal burner operates at a glowing red temperature? Thanks.

    • Redwood says:

      Hi Matt,
      There are many things that could be going on but the #1 concern is you can smell gas.
      I strongly recommend shutting the water heater off and calling a plumbing professional to examine the installation, and diagnose what the problems are with this unit.

  19. Will says:

    I have a us craftsmaster flameguard water heater that stopped working today. It was here when I bought my house over 2 years ago and this is the first issue I’ve ever had with it. I can get the pilot light to ignite, but after a minute when I release the reset button, the flame goes bye bye. I have gas so that’s not the issue. I have been looking online and on YouTube and they all seem to say I need to replace my thermocouple. My problem is I don’t know how to get to it. There’s some sort of barrier blocking access and I’m not talking about the removeable door. Help me please!

    • Redwood says:

      Hi Will,
      Your water heater is a bit different than the last one that you worked on that just had an easily removed door panel to get into the burner. This water heater is an FVIR (Flammable Vapor Ignition Resistant) model which would prevent the ignition of flammable vapors if you spilled gasoline next to the water heater for instance. To accomplish this the combustion area is completely sealed and is airtight with the combustion air drawn in through a flame arrestor. While flammable vapors may be drawn through the flame arrestor if they are ignited by the pilot or, burner the flame will not be able to travel back through the flame arrestor, and ignite the vapors in the room.

      In the event of a FVIR event happening a thermal fuse detects the increase in heat from the added fuel and shuts the unit down. In the older units the fuse is in the thermocouple and is a one time fuse which is described in the article above. In later models there is a white reset button which you press to reset.

      Which unit do you have? Do you have the white reset button on the panel sealing the combustion chamber?

      If you have the later unit press the white reset button and retry lighting the pilot light. If that works then you will probably have to clean the flame arrestor on the bottom of the water heater as well or, it may trip again. If that doesn’t work you probably need to replace the thermocouple which requires opening the airtight panel replacing the thermocouple and resealing the panel when putting it back together. the procedure for testing the thermocouple is given several times in the other comments.

      If you have the older unit without the white switch you will need to order the burner enhancement kit as explained in the article above. the thermocouple has a one-time thermal fuse in it and utilizes a left hand thread, so regular thermocouples will not work and the kit must be installed, which will then use the regular thermocouples.

      Hope this helps get you back into hot water,

  20. David says:

    I have a GCV 50 101 made by AO Smith in 2004. The spark arrestor is constantly stopping up and the only way to really clean it is to take the heater out and remove the bottom to vacuum it. Is there any safe way to remove the arrestor so this will cease?

    • Redwood says:

      Hi David,
      Removing the flame arrestor will compromise a safety system which prevents flammable vapors from being sucked into the water heater and being ignited causing an explosion and or, fire in the home. This design was required by law after incidents where flammable liquids were spilled near a water heater and flammable vapors were ignited by the water heater.

      The design of the system installed on your water heater picking up the combustion air supply from the bottom of the water heater is one of the worst designs possible in my opinion. I consider the design used by Bradford White in their Defender System to be the best design and the design used by Rheem, Ruud, and Richmond, to be second best. Both of these designs have the combustion air drawn in from the side of the water heater and are far less likely to draw in dirt clogging the flame arrestor. The difference that separates Bradford White from the Rheem family of water heaters is the Bradford White has a resettable switch that trips in the event of an FVIR event, and the Rheem water heaters use a oil filled glass vial which breaks when there is a FVIR event.

      Some of the newer water heaters in the AO Smith family come with a pre-filter, which goes around the bottom outside edge of the water heater, sealing the gap between the water heater and the floor. This filter is easier to clean, and may help prevent clogging of the flame arrestor. I would call AO Smith Customer Service at 1-800-527-1953 and see what they can offer for resolution to your problem.


      • David says:

        Good Evening Redwood,
        Yes I understand the purpose of the spark arresting system and was very disappointed when it became a fact cause I knew it would become a headache, but can it be safely removed without causing other problems?

        • Redwood says:

          Hi David,
          As a plumber legally I cannot defeat this system, try asking your home insurance company if you defeating this device would affect your insurance coverage in the event of a fire and or, explosion. If I were to do this work as a hired plumber and there was a fire and or, explosion caused by the FVIR removal the insurance company would try to recover the loss from my company. Really what you are asking is if you can safely remove a safety device, expecting an answer saying you can safely do it. You aren’t going to find that answer here.

          I would as stated earlier contact AO Smith Customer Service asking them about getting the prefilter which goes around the bottom of the water heater and on the next one you install get a better one.


          • David says:

            Just forget it… This heater was purchased in 2005, I am not a dummy, nor was I asking you to remove it. I am not stupid enough to store flameable liquids next to, in the room with, or in this case in the same building with a working gas (with a flame) anything. Sorry I came across this holier than thou site. Good day.

            • Redwood says:

              Hi David,
              Sorry you don’t like the answer, you’ll have to keep shopping for the answer you want to hear. Bad advice won’t be found here.

  21. Charles says:

    I have a Proline FlameGuard 40gal. water heater. My problem is that once you light pilot and it comes on, it might go off when its cycle is done. It might stay on a cycle, a day, or couple of days you never know. The vent on the bottom is clear and I am assuming the thermocouple is good cause, it will stay on but goes out when the cycling is done and kicks everything off. Please help, I am tired of walking up n down these dam basements steps…. And I do know assuming anything is not a good thing, assumption will get you nowhere.
    Thanks, Charles

    • Redwood says:

      Hi Charles,
      It may be a bad thermocouple or, a bad gas valve. The thermocouple when it is properly placed in the pilot flame it generates a very small voltage of 12 millivolts which holds open the gas valve supplying gas to the pilot and main burner. The button for lighting the pilot light is a temporary override which allows gas to flow only to the pilot light until it has been in the flame long enough to generate the 12 millivolts or higher. Typically this should happen within 45 seconds of the pilot light being lit.

      I would first check that the thermocouple connection at the gas valve is tight, and the thermocouple is properly placed in the holder in the burner. If it is not pushed in all the way the thermocouple will not be in the flame enough to generate the required voltage. See the picture below.

      Whirlpool Flameguard Thermocouple

      If the Thermocouple has been properly placed in the holder the next step is to disconnect the thermocouple from the gas valve and measure the voltage after the thermocouple has been in the pilot flame for 45 seconds or longer. Using a volt meter the voltage should read 12 millivolts or more. If the voltage is low it will not properly hold open the gas valve and the thermocouple should be replaced. If the generated voltage is sufficient then the gas valve has a week coil and is not holding the valve open so the gas valve needs replacement. See the picture below showing the thermocouple being tested.

      Testing Thermocouple With A Multimeter

      I hope this helps you out,

  22. Stewart T says:

    We have a FG1F4040S3NOV model water “heater.” We were having problems maybe a year ago, and called and got the burner enhancer kit. Installed it ourselves, and things worked for a while. Now, we’re back in the light, and relight, and relight cycle. Once we get it lit (holding the pilot light down for about 2 minutes, though the warnings on the heater BOLDLY say not to hold it over 1 minute), we can get some hot water, but this will only last for maybe 6 hours to 48 hours before we need to re-light.

    I’m almost positive that it is the flame arrestor that needs cleaning. However, I really have no idea how to do it. The heater is in our attic, and is sitting in a square pan. The heater itself is off-center of the pan. I have wiggled in a vacuum hose under there befre, but could not really scrape or brush anything. I have tried using a couple of small brushes, but I just can’t seem to get them to reach. Is there a video, or a picture, or do you have any suggestions of how to go about cleaning the filter? My other thought is just to take out the burner and clean it from the inside, but I get nervous bending some of those tubes too much. My other option is to call a plumber out, but I’m guessing that’s going to be upward of $200, and I’ll feel bad if its something as simple as brushing down a filter.

    Many thanks!


    • Redwood says:

      Hi Stewart,
      While the flame arrestor may be the problem, I would also recommend looking at the thermocouple as a possible cause. My sense is that the flame arrestor being plugged up would probably activate the thermal switch that was added during the burner enhancement modification. But it may also make the pilot flame too cool to keep the thermocouple working. Test the thermocouple as shown below with a multimeter.

      Testing Thermocouple With Multimeter

      The multimeter should read 12 millivolts or higher after the pilot light has been lit for 45 seconds. You should also make sure the thermocouple is properly inserted into the pilot light assembly as improper placement in the flame may result in a lower voltage being generated.

      Whirlpool Flameguard Thermocouple

      Hope this gets you back in hot water,

  23. charles says:

    American sent me two different conversion kit an American one and a Canadian one how do I tell them apart?

    • Redwood says:

      Hi Charles,
      I’m not sure, as far as I know there are different burner enhancement kits for Natural & LP Gas, and the Low NOx burners. I’ve never seen a Canadian Version of the kit, I would suspect if there is a Canadian Version it would have a CSA Approval marking and the US version would not. However, I would play it safe by calling American Water Heater at 1-800-999-9515 to be sure. Gas is not something that you want to play with and not know what you are doing, neighbors tend to find it unpleasant to have the walls of their home blown in, and the windows broken in an explosion or, attending the funeral of the family next door who died from CO poisoning.

      Play it safe, make sure of what you are doing,

  24. GLEN says:

    How can I get a “Burner Enhancement Kit” for my Whirlpool water heater FG1H5040T3NOV?

  25. Larry Bennett says:

    I have just replaced my water heater left handed conversion kit for a whirlpool. Yes it is installed as recommended but the pilot lite will not stay lite after holding the manual button down for over a minute. Everything is brand new. I have never seen that “adapter” before. is there tests that I can do to prove that the parts are good. I just don’t know what to do from here.
    Not Happy

    • Redwood says:

      Hi Larry or, Not Happy,
      We’ll have to see what we can do about changing your happiness level. The first thing I would do is recheck the installation of the conversion kit and specifically recheck that the thermocouple is pushed into the holder all the way so that it is properly centered over the pilot flame as shown in the picture below.

      Whirlpool Flameguard Thermocouple

      If the thermocouple is installed properly the next step would be to unscrew the thermocouple from the gas valve and check the voltage the thermocouple is producing while the pilot light is lit after 45 seconds of operation. Using a multimeter with alligator clip leads attach the red lead to the body (copper part) of the thermocouple. Attach the black lead to the end (silver part) of the thermocouple that connects to the thermostat. Follow the instruction to light the pilot and watch the voltage readings the meter should read 12 millivolts or more.

      If the voltage reading is lower than 12 millivolts the thermocouple is bad and you need a new one.
      If the voltage reading is 12 millivolts or, higher then the gas valve is bad and you need a new gas valve installed.

      Hopefully it’s just the thermocouple which you can get locally, if it is the gas valve you are back to calling American Water Heaters and waiting for the parts to arrive again before you can have hot water.

      Hope this helps,

  26. Joe Leskovsky says:

    I have a 6 year old G.E. water heater and the combustion air button under the burner popped up and shut off the combustion air. Can this button be reset and how.

    • Redwood says:

      Hi Joe,
      The GE uses the same system as the Rheem/Ruud/Richmond water heaters where a glass vial filled with oil inside the combustion chamber breaks when it gets too hot. Call the phone number on the sticker to get a replacement vial. You will need to have the combustion chamber taken apart to replace it, and to clean the air inlet so it will not break again.

  27. frank says:

    I have a new ( Jan 2012 ) 50 gal Whirlpool NG – FG heater. About the end of feb the pilot light started to go out. This has happen 3 times now aways at night. I can restart it with no problem. I called the help line at Whirlpool and the guy told me that this unit had to be installed with a single pipe exhaust. Mine is routed with a furnace pipe. Is this right. The house is 25 years old and 2 other water heaters have worked 10 years each until they started to leak water.

    My pipes are double walled 2 small bends by the furnace.

    Any Ideas?


    • Redwood says:

      Hi Frank,

      I’ve got a couple of questions.

      Did you install this yourself or, did you have someone install the water heater?
      If it was installed by someone I would call them back to have them fix it under warranty.

      Does the furnace have an induced draft? (A blower on the exhaust)


  28. Fred Miller says:

    I have a Whirlpool (bought at Lowes) that claims to be a US Craftmaster SG1J404073NOV (can’t find on web) that only produces lukewarm water. The pilot seems is on but never “heats” water. The electronic Honeywell controller (WV8870a 1008) flashes ok. Any thoughts? I am starting to think the old mechanical controllers were better – less parts to fail.

    • Fred Miller says:

      Turned of controller and gas. Waited about it a minute. Relit pilot flame. Appears to be working. Should be ret instructions on the unit!

      • Redwood says:

        Hi Fred,

        That was easy I guess.

        Do you have the owners manual for the water heater?

        I was looking for the Owners Manual PDF for your water heater on my computer for you when you replied. I have one for an American Water Heaters product that uses that Electronic Gas Valve that I could e-mail to you if you need it. I love the way they keep their sites updated with product information, just look for it on about 3 different sites and you just might find what you are looking for.


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