[andrewmgsa]

In my new house, the previous owners have set up 2 separate thermostats. One controls the heat and one the AC. Both are the same model/brand and they both have a switch (see picture) to toggle from Cool/Off/Heat. However, they are wired where one is solely for AC and the other Heat. Why would they not be all on 1 ? Both thermostats are in the living room but on opposite ends. it a very small 1 level house (1,100 sq feet)

 

[lenaitch]

Certainly not an HVAC guy but I have seen that before but usually with older simpler thermostats that could adjust temperature but nothing else. The switch was just used to turn on the fan to circulate the air. Perhaps the heat and a/c went in at different times and they just evolved to newer thermostats using the existing signal wires with fewer conductors. If there are enough conductors or you can fish new ones, you could likely convert one thermostat to do all and abandon the rest. No doubt smarter folks than I will be along.

 

[roughneck]

What kind of heating system do you have?
This was common for older houses that had air conditioning added on.

 

[user_12345a]

is your heating system totally separate from cooling?

 

[andrewmgsa]

newer unit (2006) and AC/Heat all in one (same fan and power source). It's from Goodman Manufacturing

 

[andrewmgsa]

2 thermostats ?

trying to change the title to "2 thermostats ?"

 

[user_12345a]

then i don't know why they did that.

to combine into one - rewiring would be necessary unless you have at least 4 wires at one of the stats.