bad gas valve

what model of heater is it? mr heater makes all kinds of propane heaters. they make kinds with thermocouples and that could also be your problem.... we need a little more info.

contractor series MH125FAV
here's a pd of the manual.
http://www.mrheater.com/upload/newsletter/MH_HS_55_60_85_125FAV%20_TRI_L%20(2).pdf
thanks!

going on the info i have I would say that you have a bad thermocouple. It is part #18 on the parts break down. that is the part that you are warming up when you hold the fuel button down for 15 seconds. it has to send a signal to the gas valve that there is a flame present for the gas valve to stay open after you let go of the fuel button.

It is the thermocouple. I hold the button in on mine and it won't start. I smell no gas. Is it the gas valve that is not opening?

I think Elvis left the forum two years ago....

Elvis left the building, but he never died.....

Too Funny.