Strangest Water Heater Problem EVER!

[oakprk]

Last year after setting up at our annual camping spot high in the Eastern Sierras, I flipped on the propane water heater switch and...nothing! Flipped it off and on numerous times, checked and reseated all the wiring in the water heater compartment and still nothing. I didn't have a meter so I couldn't check if power was going to the gas valve. After agonizing about how to heat up the water usning the generator and electric element, the DW and I went to bed. Lo and behold, in the middle of the night, we heard the familiar sound of the propane lighting in the water heater compartment! It continued working as normal for the rest of the week there. Fast forward one year, same spot, flipped the switch and nothing! Never used the propane heater since the prior year. Checked the switch with my new VOM and found 12V being passed through the switch but nothing coming from the control module going to the valve. DW remembered the previous year and started tapping everything, flipping the switch and kicking cabinets...no luck! Kicking ourselves for not having the problem repaired during the past year, we again resolved to use the generator to heat the water...until the next day. The DW walked up to the control panel, flipped the switch one more time and FWOOOOP, the propane lit and ran fine the rest of the week! So, does the control module need to be replaced or do we just have to wait a day or so before we use our propane heater????

[Oakman]

Are you sure it isn't just a bad switch?

[Bama Rambler]

Sometimes those plugin connectors on the board get a little corroded.
You can try unplugging then and replugging them a few times to see if it cleans them up.

[Flybob]

One thing I can think of that was repeated both years was that the generator was run for a while to heat water. It is possible that when you tried to light it the battery voltage was low and the controller would not start it, but after running the generator for a while, it was OK.

[oakprk]

I checked the switch this year with a volt-ohmmeter. It was doing it's job providing 12V to the control board when switched on.

A bad switch wouldn't explain why it started working after a day and continued for a week!

[oakprk]

Originally Posted by Bama Rambler

Sometimes those plugin connectors on the board get a little corroded.
You can try unplugging then and replugging them a few times to see if it cleans them up.

The control board/module is located behind the water heater/tank. There's no easy way to access it.

[oakprk]

Originally Posted by Flybob

One thing I can think of that was repeated both years was that the generator was run for a while to heat water. It is possible that when you tried to light it the battery voltage was low and the controller would not start it, but after running the generator for a while, it was OK.

We tried turning it on first shortly after setting up when the (new) batteries were charged after the long drive. We considered using the gen to heat the water but never turned it on before the propane started working.

[New2minilite]

Having same issue 2018 2509s kicks on runs for a few seconds shuts off

[tom2t]

It may sound crazy, but could it be an issue with the thinner air at higher altitudes? Once the ratio of propane and air stabilized in the piping it was able to burn efficiently? Just a thought.

[oakprk]

Originally Posted by tom2t

It may sound crazy, but could it be an issue with the thinner air at higher altitudes? Once the ratio of propane and air stabilized in the piping it was able to burn efficiently? Just a thought.

We couldn't help thinking it has something to do with the altitude. Your explanation is the closest thing to making sense! But, wouldn't it still attempt to light and, if not, leave the red fault light on? No red light when the problem occurs.

[richard6335]

It is the propane. Mine does the same thing and also happens with the oven. Propane travel time to igniter, and I will bet you never had the gas turned on until you were ready to heat water??

[oakprk]

Originally Posted by richard6335

It is the propane. Mine does the same thing and also happens with the oven. Propane travel time to igniter, and I will bet you never had the gas turned on until you were ready to heat water??

The propane was on for hours, for the refrigerator, and the water heater is closer to the tank than the refrigerator. Also, if the propane doesn't ignite, you should have a red fault light on, we don't get one. :-/

[tankroady]

I have the same issue at sea level with my frig. I just fire up the stove till it lights the the frig kicks in.I blame it on air in the line. I have checked for propane leaks, but can"t find any.I have a LEL monitor to check, old way to do this is with soap and water.Slow leak somewhere.Could be when I change bottles.

[HangDiver]

I had the exact same problem yesterday camping with electrical hook up. I fired up the HW tank on propane and electric (for faster heat up). Shut propane off. DW went to take a shower later that night so I flipped the propane on again - nothing. The propane side of the HW heater has worked flawlessly up until last night. This morning I tried it again and it fired right up. I had full propane tanks and propane to all my other appliances without issue. Stumped.

[oakprk]

Originally Posted by HangDiver

I had the exact same problem yesterday camping with electrical hook up. I fired up the HW tank on propane and electric (for faster heat up). Shut propane off. DW went to take a shower later that night so I flipped the propane on again - nothing. The propane side of the HW heater has worked flawlessly up until last night. This morning I tried it again and it fired right up. I had full propane tanks and propane to all my other appliances without issue. Stumped.

Did the red light on the switch come on and stay on or did it not come on at all?

[TitanMike]

With no fault light on the control board is not asking for more heat which is not being answered by "flame". Could be a faulty temperature sensor perhaps?

Other option might be to turn the switch on about 8 hours earlier

[HangDiver]

Originally Posted by oakprk

Did the red light on the switch come on and stay on or did it not come on at all?

No red light at all. Checked circut breakers/fuses. No clicking of the igniter, nothing. It seemed like it was just dead. Then this morning it fired right up like it always did.

[HangDiver]

I should have made this more clear in my original post..... I turned both electric and propane on to wash dishes, then shut both off. Hours later that night I turned them on again but propane side didn't light. I suppose its possible the water temp in the tank was still warm enough? Doesn't seem likely to me but now I have something to test for.

[TitanMike]

Originally Posted by HangDiver

I should have made this more clear in my original post..... I turned both electric and propane on to wash dishes, then shut both off. Hours later that night I turned them on again but propane side didn't light. I suppose its possible the water temp in the tank was still warm enough? Doesn't seem likely to me but now I have something to test for.

Very likely you have a well insulated tank. That's a good thing

My experience has been that when things go bad they usually stay bad, not reviving themselves later in the night.

BTW, simple test. Run the hot water and collect it in a clean jug so you can pour it back in the tank if you need to. When the water is cold enough in the tank the propane should light. If it doesn't, and the water from the faucet runs cold, then you know you have a problem.

[camper70]

Just an idea. I had a similar problem but found my bypass was still open from the dealer. These systems do have a high temp and high pressure shutoff for the system which could keep the propane from lighting.