I have hot water heat. There is a register in my garage with a fan attached to circulate the heat. There are currently 2 thermostats (one for the fan and one to call for heat). I would like to put one thermostat on that can run the fan as well as call for the heat.

There is a red and a white coming from the fan transformer. There is also a red and white coming from the furnace to call for heat.

I have a one stage thermostat which calls for a red, yellow, green and white wire. Which terminals on the thermostat (Y - G - W - R) are for the furnace and which is for the fan? Which is hot and ground for each?

Can your fan be controlled by low voltage 24Volts without using a relay?
What powers and turns the fan on now?
Red wire goes to r on tstat ,white wire goes to w on tstat ,this will control your furnace

The fan is controlled by a low voltage (24 volt) thermostat now. I is a 110v fan. There is a tranformer between the fan and the thermostat.

Your Furnace wire will go to R and W as polarity doesn't matter
The fan wire will go to terminals G

That's All

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