[wmsward]

We have to turn the circuit breaker off in the summer because the furnace comes on. Has done this with all three thermostats we have used over the last ten years. AC is separate unit on separate thermostat

 

[HvacWiz]

Is this a electric or gas furnace?

 

[COLDIRON]

Heater on

Sounds like wrong thermostat or wired for cooling.

 

[Chemist1961]

Agree with Sultini. Sounds like the stat was set to cylce air in fan mode at higher temp and someone has wired it to kick on heat instead.

 

[ScottR]

or wired for cooling.

That means it wouldn't work in the winter though..?

AC is separate unit on separate thermostat

I have to ask ...

Does the heat kick on only when you're running the AC?

Or does the heat still kick on even if you set your heating T-stat to 90deg.?

 

[biggles]

if the heating stats are all set down to 50F or as low as they can be set you should have no heating during the summer.if the heat starts right off the bat when the cooling starts it is a control mis-wiring.if the heating stats are solid state and set for heat/68F they might be anticipating a call for heat as the cooling drops the temperature within the house

 

[wmsward]

Thanks All;
Furnace is propane. It runs normally during winter. It's on off cycling has no correlation operation of AC which is on separate thermostat and a separate unit.
When it gets up in the eighties in the single wide the furnace will kick on. Not necessarily every time as I have not monitored that yet. There are two wires to the thermostat I think. I have changed it twice from original mercury switch to current programmable thermostat.
I have no recollection of whether this was happening before or started after I replaced motor in furnace six or so years ago.

 

[wmsward]

Heat set in range of 58 to 72 degrees. More likely to come on in high eighties when Air conditioning is off as AC is usually set at about 80 +/- 2*