I have a mobile home with an Intertherm furnace, used for both heating ond cooling. I have one T-stat that controls which function is to be used,(heating/cooling). This one controls the cooling temp,and fan. I have a second T-stat that controls the heat temp. It is an old two wire mechanical and I would like to replace it. Could anyone tell me of any replacement ones.

Usually any heat only thermostat will work. Does your furnace have a heat/off/cool switch on it?

YES. THe main t-stat has the heat/off/cool switch. I purchased a very basic heat only, but with negative results. The one I purchased was a 24volt. Is it possible that the old heat t-stat is dry contact only,spring tension operated.

Is it possible that the old heat t-stat is dry contact only,spring tension operated.

Yes

I'll check on that. Thank you very much for the info.