Hot Water Heater Problem

[OverkillYJ]

I have a propane hot water heater that isnt working. I have fixed and installed quite a few furnaces and hot water heaters, but this one stopped working, and the pilot wont stay lit. I set it to pilot and hold down the button, the pilot ignites, then when I try to switch it to the on position the pilot goes out as soon as I release the button. I am assuming I should order a new valve for it, but since that will take a few days to get here and I have no hot water I figured I would get some more opinions. Maybe I missed something?

Thanks for the help.

 

[larry4406]

Bad connection on the thermocouple or failed thermocouple. Easy to replace.

 

[Jim greengo]

Does it have a roll out/reset switch on front of it by any chance?
Otherwise I'd pull the thermal couple out and clean or replace it before attacking the gas valve.

 

[The Cobbler]

very likely the thermo couple gone bad

 

[gmcgeo]

along with others saying the thermocouple, try some steal wool and clean the thermocouple first before replacing. it will get white dust all over it and kind of insulate it.
while you have it out blow the pilot out with canned air so its clean.

 

[tdkkart]

along with others saying the thermocouple, try some steal wool and clean the thermocouple first before replacing. it will get white dust all over it and kind of insulate it.
while you have it out blow the pilot out with canned air so its clean.

This will frequently fix this problem

 

[fitter30]

Thermocouple puts out 35 mv. If you have a meter with a mv scale checking for voltage is easier with two people on hold button down the other for the meter. Pilot orfice clean? If there wires going to another safety check the connections and resistance across their termials. Should be close to 0 ohm.

 

[gmcgeo]

Thermocouple puts out 35 mv. If you have a meter with a mv scale checking for voltage is easier with two people on hold button down the other for the meter. Pilot orfice clean? If there wires going to another safety check the connections and resistance across their termials. Should be close to 0 ohm.

350-800 mv

 

[joel63]

350-800 mv

For the Power Pile.

 

[gmcgeo]

For the Power Pile.

right

 

[fitter30]

right

Round pp 750 mv
matchbook 350mv

 

[James-W]

As has been mentioned, what you have is a classic thermocouple failure. Just replace it and you will be back in business. They don't cost very much, usually less than $10 at most hardware stores, a little less at big box stores.

 

[Walkers]

A single thermocouple should have a minimum reading of 25mv, max of about 30. The mag head drops out below 25mv. Reading them is easy, but inaccurate when you unscrew them. There is a little adapter for reading in situ. Most of the time you can blow out the pilot assembly with compressed air (I had a piece of rubber hose with a piece of 1/4” aluminum tubing stuffed in the end to blow them out back in my serviceman days) then replace the couple if it still doesn’t stay lit. LP was a little worse than natural gas for building up ash. Little tiny bugs dying in the air hole caused problems too.

 

[Meursault74]

Might be the thermopile, same but different,

I have a thermocouple on my water heater. My brother had issues with his fancy water heater and it had a thermopile as it needed more energy to run the fancy features. I remember taking voltage reading with the flame on it, but don't recall the readings at the moment. The company sent out an entire kit (thermopile and pilot) under warranty and I swapped out the whole thing.

Thermocouple vs. Thermopile: A Complete Comparison | Linquip

Why is the comparison between Thermocouple vs. Thermopile too important? The main difference between Thermocouple and Thermopile is the method of measurement.

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