gas wall heater won't stay on

[lilafter]

hi, i have a gas wall heater that has persistantly given me problems for the last few years. i live in los angeles so heating is a short term issue and one reason for procrasination.

i changed the thermopile last year but it didn't fix it. the pilot light stays on but goes off when i try to use the heater for any length of time- varies from a few minutes to a couple of days.

i had the gas co come in and check a few times. one mentioned the safety mechanism (?) near the top close to the vent is bad? i also changed the wires(2 red) to the safety mechanism b/c they were loose and possibly causing the heater to trip off early.

i removed the pilot generator with thermopile and the round thing(safety mech?)- did shut the gas off. and plan to take it to my local hardware store. hopefully they can help me.

any suggestions? am i on the right track?

[wayneferr]

Gas Heater

I would be looking at the thermocouple at this point to make sure you have the thermocouple correctly positioned. The thermocouple needs to be positioned in a way so that the first 3/4 inch is emersed in the pilot flame when you are holding down the button to light the pilot light. You see the thermocouple generates a very low amount of electric energy from the flame of the pilot which transfers to the gas valve. When this current is passed to the gas valve properly it energizes the safety mechanism in the gas valve. When the safety mechanism is energized the gas valve it proves there is a flame present allowing the gas valve to allow gas to flow on a call for heat. So the moral of the story is too make sure you have the thermocouple correctly positioned within the falme from the pilot. If all else fails repost your reply, and I will try to walk you through this repair.

[lilafter]

now i have a gas leak!

i took apart the pilot generator. when i put it back together, i noticed a small gas leak between the gas line and pilot where they screw in together. its as tight as it can be but it still leaking gas. it bubbles with soapy spray and lights up a small flame when i tried to pilot the gas on.

what the heck did i do? how can i fix it? i haven't been able to check if the safety valve is faulty b/c of the leak. i can't believe i made it worse!

[HayZee518]

the thermopile is what they call a j-k thermocouple. what it is - is two dissimilar metals fused at one end, when heated produces a small dc current. the bulb end - what you see is one side of the thermocouple, inside is a small wire which is the other lead. At the end that goes into the valve is a small bulb, an insulator a copper washer and a gland nut. This mates with a tiny electromagnet that opens a spool valve inside the gas valve. When you push the "press for pilot" it allows the spool to move a little bit to open the pilot gas port. With enough dc current to the spool valve, when you release the button, the valve stays open and advances further opening the main gas supply and ignites the burner bib. Any piece of dirt within the valve will, a) keep the valve from opening, or 2) keep the valve wide open. The gland nut is steel and the valve body is white metal and it is very easy to cross thread this joint, which may result in a leak. You may need to get a new valve.

[JCA1]

remove the pilot assembly again, shoot some contact cleaner right down the throat of the pilot, then back through the pilot line inlet. Do not spray any contact cleaner into the heater or any part/line/etc. of the heater, the pilot assembly only. Let it sit for a little while and reinstall it. If this dosen't fix your problem post back and we'll talk some more.