Duo-Therm themostat problem/question

[Ned]

Hi all, (I posted this in the MH and TT sections too)
I have a problem with one of the thermostats on my coach. It's a Duo-therm ducted AC with furnace and heatstrip functions. The thermostat looks like this:

The problem I'm having is: it functions only when the temp setting is between approximately 80 and 90, no matter what the inside temp is. It works, but the setting doesn't match truly what the inside temp is. This makes it difficult to set it to the temp you would want it to be.
Any ideas what might be wrong? I'm not certain, but think the actual thermostat is located in the unit in the ceiling...that's what I hear "click" when the temp setting is adjusted.
If anyone has encountered this problem before and/or knows a fix, please help.

thanks a bunch!!

[Ned]

Hi all, (I posted this in the MH and TT sections too)
I have a problem with one of the thermostats on my coach. It's a Duo-therm ducted AC with furnace and heatstrip functions. The thermostat looks like this:

The problem I'm having is: it functions only when the temp setting is between approximately 80 and 90, no matter what the inside temp is. It works, but the setting doesn't match truly what the inside temp is. This makes it difficult to set it to the temp you would want it to be.
Any ideas what might be wrong? I'm not certain, but think the actual thermostat is located in the unit in the ceiling...that's what I hear "click" when the temp setting is adjusted.
If anyone has encountered this problem before and/or knows a fix, please help.

thanks a bunch!!

[RV Wizard]

Recommend you replace t"stat. See MH section for more detail.

[John Harrelson]

Hi Ned,
After ten years of working perfect, I had to replace my thermostat kinda like yours.

The original stat was a combo unit that controlled both the AC and the furnace..

The furnace side quit working and rather than replace that expensive stat, I just cut off the wires to it that controls the furnace and installed another stat right below the old one to control only the furnace..

Now I have two stats and no problem..

best of luck,
John

[Lance-a-Lot]

Your thermostat photo looks like the same thermostat in our Lance. It acted the same way and we had our dealer order a replacement that we installed ourself. No problems since then.