I have a pro-com wall mount lp heater. I've had it for 4 years now it's always been flawless. It is our secondary source of heat. We only use it when we leave the house for extended times. This year the pilot light started going out on it. So I pulled the cover off and started looking. If it's just on pilot the pilot light will stay on. I believe because it has enough contact on the thermocouple. The edge of the flame just barely licks the top of the thermocouple. But when I kick it onto heat and the burner lights up I guess my pressure drops cause the pilot no longer has contact with the thermocouple. It's about 1/4" away and everything works for about 10 seconds and it kicks everything off

I took the line off between the pilot and the manifold and blew it out.
Gas is at 37% so we should be good there.
Help would be appreciated.

It has a nice blue flame on the pilot also.
Thermocouple is not really adjustable to where I could move it closer to pilot. Possibly I could tho

Ok, first check the pilot orifice to ensure it is not clogged. Next there should be an adjustment screw for the pilot flame somewhere on the gas valve. It will probably have a screw or cap over it. Most of the them I adjust on water heaters and boilers are allen screws but your gas valve may be different. And you can always call the manufacturer and ask. They should have a tech support person that can help.

Where is the regulator at? Mine does the same when the regulator freezes up.

wont hurt to bend the bracket on the thermocoupler so the pilot flame is making maximum contact.

Iwould also say you have a froen regulator.

Thermocouple is going bad need to replace it.

fought this forever , the pilot orifce screws into the oxygen sensor , blowing this out did not help but cleaning with a can of carburetor cleaner did . pilot would be small and go out befor .i believe different chemicals had burnt into it and caused low oxygen at the pilot ,it had been used in a print shop . has never failed since

WWC, you said the thermocouple is "going bad." I don't think thermocouple performance degrades over time,I think they either work or they don't. Thermocouples work because a current is generated due to a temperature difference. When they fail it is because a wire breaks and no current flows. In an LP heater the thermocouple protective function is bypassed when you light it because the temperature difference is not there until the fire burns for a few seconds. If the thermocouple has failed, the gas will auto isolate as soon as you release the bypass.

This might help. https://www.youtube.com/watch?v=1y-Iw9ZIPDg

Edp I had one on a modine furnace go bad one year and it would produce just enough ,had only half of a pilot or in other words a lazy pilot that was the only one that did it like that like you said usually it either works or it doesn't that one time was a fluke but it did happen keep looking and cleaning every thing .

JohnC x2

Just a thought some of those units have a oxygen sensor could it be that ? Poor fuel if possible or bad oxygen sensor.

I would try cleaning the orifice with a Q tip and rubbing alcohol.

2X this or a can of PC air blaster might do the trick too.

Update- I pulled the line off again blew brake cleaner down the line also brake cleaned the orifice and blew it out. Put it back together and everything is in working order. Got a nice bigger blue flame. Thanks folks.

We heat with two of them, and have to do this a couple times a year.Just clean them up and they go back to working like new.