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[wissel12]

I need help with the wiring of a unit heater in my basement.  The heater is plumbed  into the existing boiler. There are three zones in the house. When a thermostat calls for heat it opens a zone valve and turns on the the pump. My question is the unit heater has 115 wire to it. There is a switch to turn the fan off and on. How can I get a thermostat to turn the fan off and on, and also open the zone valve and turn the pump on?

The switch is just a light switch.  The unit heater was there when I bought the house. I don't want the fan to run all the time.

[slimjim]

Leave the pump and zone valve alone! go to the hardware store and get a line voltage thermostat, install it in place of the light switch.

[wissel12]

How will the water circulate in that zone?

[slimjim]

The same way it does now, think of the line voltage thermostat as a temperature sensing light switch, that is all it is.

[wissel12]

Okay Thanks

[RSI]

Just connect the fan to the same power as the pump. You don't need to buy anything else.

You should check the rating of the circuit that is running the pump and make sure it can handle the extra load. It probably can but if not, just add a relay.

[slimjim]

   I think what he is saying that that whole zone is controlled by the light switch

[RSI]

The OP said there is a thermostat that turns on a zone valve and pump. I assumed he wanted that same thermostat to turn on the blower also. I am guessing the zone valve end switch is being used to turn on the pump.

[slimjim]

You may be right, perhaps I misunderstood,if so good catch.

[RSI]

I just read it again and now I am not sure either.

We need to know if there is an existing thermostat or if you want to add a new one.
Also, is there a pump and zone valve already there or will you be adding that also.

[wissel12]

You got it RSI.  Everything is there but a thermostat. The fan motor runs when the switch is turned on.

I want to now how to control everything with one thermostat.

The main level and top level each have there own thermostat. There is one transformer, one pump and three zone valves.
There is no Thermostat in the basement. Does that help?

[RSI]

Is anything currently controlling the pump and zone valve that you want to come on with the new thermostat?

[wissel12]

I don't think anything is controlling that Zone in the basement.

[RSI]

Ok, then you will need to check if the zone valve has an end switch. If you are not sure, get the model number off it and I can look it up.

Also check if there is a va rating on the transformer. You will need to make sure it can handle another zone valve.

If it doesn't have an end switch or your transformer is too small to handle another zone valve, I would buy a fan center relay.
Another option would be to just use a line voltage thermostat like Slimjim suggested but you will need a separate 24v transformer to run the zone valve.

[wissel12]

If you have a voltage thermostat, can you run a 24v transformer from it.  I have a voltage thermostat.

I will check the rest out.