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BFL13's avatar
BFL13
Explorer II
May 24, 2020

Water Heater Gas Valve Stuck Open UPDATE-Bench Test

Updated 25 May
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Was having trouble getting my 1991 OEM Atwood WH to light for months, worked sometimes, very frustrating. Got some parts off a newer WH including the gas valve and swapped things around and thought it was a success.

However, since then could smell propane a little, including inside the rig. No LP alarm, not that bad of a leak I guess. After much trouble shooting, I narrowed it down to be a gas smell at the burner end even though the WH was turned off. (For a while I was convinced it was at the gas inlet end and tried to fix that--more yellow tape, tighten--not it)

Had to be the outlet end. I tried to light it with a BBQ lighter, and it lit with a small blue flame that stayed on! I also found the seal where the gas line comes out front was not sealed properly, so that must have been how the smell got inside the rig. Fixed that.

Another clue was that when first lit, it made a bang so I suspected a "delayed ignition" type event where fuel accumulates before the spark. That can be very bad!

Swapped the old gas valve back in, and discovered its ground wire was loose so that was why it was not working right all that time before. All good now.

Sooo--the question is, with the newer gas valve (photo) how can it be stuck open? Can it be fixed so it can be kept as a spare, or is it toast?

Thanks.

Photo of newer valve that is stuck open



Photo of the OEM valve, now back in and working

  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    May 24, 2020
    LP System only has 0.4 psi so iof gas is leaking thru gas valve then it is NOT salvageable.

    Takes BOTH solenoids to be energized to OPEN the gas valve
    When DC is removed springs close the gas valve
    Able to light and have small flame at gas valve means it is leaking thru with ONLY 0.4psi

    Course you have nothing to loose so disassembling it won't hurt anything
    Caution: Gas Valves are classified as NON-Serviceable
  • BFL13's avatar
    BFL13
    Explorer II
    May 25, 2020
    Thanks. To bench test it, if I can get it unstuck with spray and banging on it, will it operate by putting 12v to the positive wires that go to the ECO and the "chassis" of the valve where the neg wires are connected?
  • Gdetrailer's avatar
    Gdetrailer
    Explorer III
    May 25, 2020
    Hmm.. I wonder what happened to the poster from CA that always spouted off about the CA requirements for a "certified" propane technician to repair propane systems? Looks like you have voided CA "laws".. :E :B

    I am with Old Biscuit, while there have been a couple of folks who have torn down and repaired those valves and gotten them to work. Unlike those folks I really do not feel they are worth gambling my life on.

    I suspect however that valve may not be as reliable as it should be even if you do manage to repair it.. How comfortable are you with it once and a while leaking again down the road? Explosions can be sometimes fun, but not so much when it is something you are living in..

    Sometimes it is money, time, safety ahead to replace with new rather than MacGyvering a mission critical part into working.

    Chuck the leaky valve in the garbage and don't look back.
  • BFL13's avatar
    BFL13
    Explorer II
    May 25, 2020
    Concur that I would not trust it if I got it working again.

    How common is it for these valves to be stuck open? Should I worry about the older one back in there now? What about the valves for the fridge and furnace? Can they get stuck open?
  • dougrainer's avatar
    dougrainer
    Nomad
    May 25, 2020
    1. Atwood Gas Valves(older) have a common problem with small leaks. Even with a dual solenoid. This is after years of operation. I always do a liquid bubble leak test FIRST on an Atwood Gas valve orifice when my manometer test shows a small leak on an older RV. I am right about 50% of the time.
    2. There is no REAL law or regulation that states a Consumer CANNOT work on his Gas appliance or system. It is just NOT a safe practice to do. But, there are rules and regulations in a lot of States, that dictate you must be licensed to install/repair, gas appliances and systems/piping in a commercial activity. Failure to be licensed and something happens you can be sued. Also the Licensing Agency can fine you if you work on gas systems if the law requires you to be licensed.
    3. Gas parts are not serviceable. You cannot even buy replacement individual valve parts. I WOULD NEVER ATTEMPT TO REPAIR ANY GAS VALVE, EVEN THO I KNOW WHAT I AM DOING AND I AM LICENSED. JUST NOT A SAFE PRACTICE. AND AGAINST TEXAS STATE LAW AND REGULATIONS. Doug
  • BFL13's avatar
    BFL13
    Explorer II
    May 25, 2020
    If the fault is the valve won't open, you know something is wrong and will eventually find it . In this case with it stuck open, the WH worked ok and it was some time before I noticed anything was wrong-- can be dangerous.

    So I need a routine check of the WH, fridge, and furnace to catch this a lot sooner after it happens if it happens again. Sniff test at least.
  • Gdetrailer's avatar
    Gdetrailer
    Explorer III
    May 25, 2020
    BFL13 wrote:
    If the fault is the valve won't open, you know something is wrong and will eventually find it . In this case with it stuck open, the WH worked ok and it was some time before I noticed anything was wrong-- can be dangerous.

    So I need a routine check of the WH, fridge, and furnace to catch this a lot sooner after it happens if it happens again. Sniff test at least.


    You have a 1991 appliance, a 29 yr old device which is exposed to the great outdoors.. From your pictures it has considerable rust on the DSI ignitor/flame detection parts. The valves you show have considerable amount of weathering, consistent with winter salted roads..

    You HAVE gotten your money's worth out of it for sure.

    I suspect any valve has the potential to fail in open or closed position, generally though electrical gas valves are supposed to fail in the closed position but hey, anything can happen. Things like moisture content in the propane supply can corrode the internal parts and the oils in the propane supply can gum up internal moving parts.

    I would have to say, that given the age of your rig, just a periodic sniff test should still suffice, I wouldn't think you would have to check every day for the most part.
  • BFL13's avatar
    BFL13
    Explorer II
    May 25, 2020
    The floor level LP alarm didn't do any good at all. I tested it with real propane from a BBQ bottle and it worked, so that's fine, but it is nowhere near any of the three actual propane burners reached from outside access doors. The stovetop and oven is all that is inside.

    Not sure what would have to happen to create a cloud of propane by the LP alarm inside in the middle of the RV at floor level. Have to be the stove I guess.

    I have a fire alarm and a CO alarm up higher which also work when tested (no actual CO test done, but fire alarm goes off if smoke comes in the door when BBQing)
  • Gdetrailer's avatar
    Gdetrailer
    Explorer III
    May 25, 2020
    Generally anything with propane connections/combustion chamber that is exposed to the outside air and sealed off from the inside, that propane will drop and hug the ground level and be dissipated by the wind or or if no wind will pool around the lowest level of the ground..

    In other words most likely will not enter the inside of your RV to levels high enough to trigger a propane alarm unless you had a cylinder/regulator malfunction large enough to create a big heavy cloud of propane fast enough to engulf and surround your RV..

    Propane alarm would be more like monitoring for propane pooling from INSIDE propane connections and in most cases your stove/oven connection and or valves.
  • BFL13's avatar
    BFL13
    Explorer II
    May 25, 2020
    Bench tested the stuck valve (just to see what happens)

    Assumed it was still stuck open, removed the orifice--you can see the valve mechanisms inside--seem nice and shiny, clean.

    Poured some mineral spirits down the inlet, nothing came out.

    Put 12v to both pos wires at once and to the two green wires bolted together to the valve body. Loud click, remove 12v click, lots of clicking. You can see things moving in there.

    Tried to pour some spirits in with the 12v power on---it came out the orifice end so it is open with 12v power on, as it should be.

    Took both green wires off and put power to each one at a time--clicking with either one.

    CONCLUSIONS
    1. It was stuck open, so I must have banged it or whatever removing it and after that.
    2. It works now and both solenoids are working.
    3. Yes you can bench test a gas valve
    4. I would not trust this one, but could use it as a temporary field repair spare, doing a smell test each time before lighting the WH so not to have a surprise delayed ignition event (explosion)

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