Hot water heater not working on propane.

[DOUBLETROUBLE]

We have an '89 Jayswan and the hot water heater stopped working on propane a couple years ago. Pilot light won't stay lit. Last year I replaced the pilot burner and thermocouple and it still isn't working. I can get the pilot light to light while holding the valve down but it won't stay lit once I release it and try to turn it to "on".
Our hot water heater is equipped with an electric element as well but I prefer the propane burner as it recovers much faster.
Any ideas? I really hope I don't have to replace the entire gas valve as they're expensive and looks like a real pain to do.
Might just get a new thermocouple and try that. I don't belive there is an adjustment for the pilot light to maybe increase the flame? It burns blue so I would think it's hot enough to trigger the thermocouple.

[Mikec557]

Originally Posted by DOUBLETROUBLE

We have an '89 Jayswan and the hot water heater stopped working on propane a couple years ago. Pilot light won't stay lit. Last year I replaced the pilot burner and thermocouple and it still isn't working. I can get the pilot light to light while holding the valve down but it won't stay lit once I release it and try to turn it to "on".
Our hot water heater is equipped with an electric element as well but I prefer the propane burner as it recovers much faster.
Any ideas? I really hope I don't have to replace the entire gas valve as they're expensive and looks like a real pain to do.
Might just get a new thermocouple and try that. I don't belive there is an adjustment for the pilot light to maybe increase the flame? It burns blue so I would think it's hot enough to trigger the thermocouple.

I know just enough to be dangerous. Before I type out a long explanation, that applies to only one kind of water heater.., let me ask:

When you're looking at it with the door removed do you see a circuit board about the size of a pack of cigarettes? If so, is there a brown wire running from the circuit board to a couple of objects?

If I can find a picture of what I'm trying to describe I'll post it. Mean time, post a picture showing the entire water heater with the door off.

[Grumpy]

The blue flame may be your problem,

The flame should strong enough to cover about 1/2 inch at the end of the thermocouple tip. If the flame is too strong and not adjusted correctly, it will be blue and may make a hissing sound as the flame crosses the thermocouple.

[Mikec557]

Originally Posted by DOUBLETROUBLE

We have an '89 Jayswan and the hot water heater stopped working on propane a couple years ago. Pilot light won't stay lit. Last year I replaced the pilot burner and thermocouple and it still isn't working. I can get the pilot light to light while holding the valve down but it won't stay lit once I release it and try to turn it to "on".
Our hot water heater is equipped with an electric element as well but I prefer the propane burner as it recovers much faster.
Any ideas? I really hope I don't have to replace the entire gas valve as they're expensive and looks like a real pain to do.
Might just get a new thermocouple and try that. I don't belive there is an adjustment for the pilot light to maybe increase the flame? It burns blue so I would think it's hot enough to trigger the thermocouple.

Does your water look like this? This is an Atwood, now known as Dometic.

Edit: sorry. One of my synapse just fired. What I know about is DSI, direct spark ignition. You're talking about a standing pilot light and a Thermocoupler. Disregard my input.

[muckinfuss]

Something to try with a lit pilot problem in order of most likely to least:

if you had your propane tank refilled prior to this problem showing up, it may not have been bled properly before handing it back to you. A primary cause of poor flames.

Go/no go...Carefully pull the thermocouple and with 000 steel wool polish the working end that is in the flame and reset to try.

Go/no go...(I've encountered out of the box failures) Three ways to test a thermocouple with a multimeter:
Test 1: Select the ohms or resistance option on your multimeter. Place one test lead on the side of the thermocouple and the other to the end that screws into the gas valve. If the thermocouple has proper continuity, a small resistance reading should be visible on the multimeter. Many multimeters also indicate continuity with an audio alert. If the reading on the multimeter indicates an "OL" reading, the thermocouple does not have continuity and is therefore not usable. A high resistance reading, such as 40 ohms, suggests that the resistance will cause problems and the thermocouple should be discarded.
Test 2: Turn your multimeter to millivolts to perform an open circuit test. Place one of the test leads of the multimeter on the side of the thermocouple and the other to the end that enters the gas valve. Ignite a lighter, or other heat source with a flame, at the opposite end of the thermocouple. Thermocouples designed for residential gas appliances, such as fireplaces, water heaters and furnaces, are made for 30 Millivolts. The reading should be between 25 and 30. Anything under or hovering around the 20 millivolts mark means the thermocouple needs to be replaced. Discretion should be used if the reading is between 21 and 25.
Test 3: For this test you need a thermocouple adaptor. Know a plumber? Perform a closed circuit test using the thermocouple adapter to achieve a true performance ability under load. It is easier to perform this test using crocodile clips attached to the test leads. First, attach the thermocouple adapter to the gas valve in the thermocouple's spot. Then attach the thermocouple as normal with the exception that the end that would screw into the gas valve will screw into the adapter. Turn the appliance on and place a crocodile clip from the multimeter to the side of the thermocouple. Attach the other crocodile clip on the screw that extends out of the side of the adapter. The reading should be within 12 millivolts and 15 millivolts. Fewer than 12 millivolts signifies that the thermocouple is defective.

Go/no go....if no go, replace with a standard thermocouple from any mass outlet (HD,ACE, etc.) take the old to match the length as close as possible. Install...

Go/no go...no go, you may have a bad pressure regulator on your propane. They can be tested to the required 11psi output, but a new replacement may end up faster, better, cheaper.

[SmokerBill]

Originally Posted by muckinfuss

Go/no go...no go, you may have a bad pressure regulator on your propane. They can be tested to the required 11psi output, but a new replacement may end up faster, better, cheaper.

Muckinfuss, 11psi propane pressure would cause all kinds of problems. Don't want to see someone get hurt.

It's actually 10.5 to 11 inches of water column, which is close to 0.5 psi.

This image shows how to build a tube manometer, and the page link instructs how it's used in an RV.

https://rverscorner.com/manometer.html

[muckinfuss]

Still on first cup of coffee. thanks for the catch.

[SmokerBill]

No problem. I'm surprise that I caught it myself! LOL

I've had 4 cups so far...

[skids]

Great info regardless.

[Kahoneys]

Why is everyone trying to heat hot water? I heat cool water but once its hot our heater shuts off. I know I am going to be unfriended by lots of people but I had to say it.

[skids]

It’s commonly called a hot water heater and everyone knows what your talking about even though it is a redundancy.

[DOUBLETROUBLE]

Thanks for all the replies. I won't be able to get back to it until Friday but I will report back what I find.
I still have use of the electric side if needed but would rather have a gas cold water warmer. Hade to say it Kohoneys!

[Kahoneys]

Originally Posted by DOUBLETROUBLE

Thanks for all the replies. I won't be able to get back to it until Friday but I will report back what I find.
I still have use of the electric side if needed but would rather have a gas cold water warmer. Hade to say it Kohoneys!

[DOUBLETROUBLE]

I got out there for a few minutes today. Got a pic of what I have. The thermocouple was hot to touch after holding down the pilot button for a few minutes. So I think the flame may be hot enough. I will pull the thermocouple tomorrow and try to test it.

[Mikec557]

Originally Posted by DOUBLETROUBLE

I got out there for a few minutes today. Got a pic of what I have. The thermocouple was hot to touch after holding down the pilot button for a few minutes. So I think the flame may be hot enough. I will pull the thermocouple tomorrow and try to test it.

Grumpy is right about the Thermocoupler having to reside "inside" the flame. I once had a cabover camper circa early 70s. The furnace had a screw head flat/flush on the top of that silver/gray box. Turning it slightly would make the pilot flame rise or lower such that you could make sure the tip of the Thermocoupler was inside the flame.

[DOUBLETROUBLE]

Mine has what appears to be an adjustment also. I didn't mess with it though.
The pilot burner and thermocouple were nee last year, would a new pilot burner need the pilot light adjusted?

[Mikec557]

Originally Posted by DOUBLETROUBLE

Mine has what appears to be an adjustment also. I didn't mess with it though.
The pilot burner and thermocouple were new last year, would a new pilot burner need the pilot light adjusted?

That, I don't know. It may be influenced by the propane pressure (11 inches of water column) mentioned above.

But if a 1/8-1/4 turn of the screw made the pilot engulf the thermocoupler, I'd take it.

Do you know hold old the furnace is? Maybe you mentioned it above but I can't see that while typing...

[DOUBLETROUBLE]

I don't know for sure how old it is. Maybe original to the camper? Not sure.

[DOUBLETROUBLE]

Pulled it apart this morning. Flushed out the tank while I had things apart. And cleaned things up a bit.
Tested the thermocouple with a meter set on mv400ac and put flame to it (on a bench of course and not grounding on anything conductive) and had no voltage reading using a lighter. Tried a hand held propane torch and still same. Gonna go to camping world and find a new thermocouple and try that. Fingers crossed.
Hopefully I don't accidently wonder into a nice used fifth wheel. Might get myself into trouble......

[DOUBLETROUBLE]

Installed a new thermocouple and pilot light, it's came in a kit. It still isn't working. My guess, the gas valve? The gas stove top works fine so I ruled out the tank valve and regulator.