Adding infloor heat to existing boiler

[andy1234]

Hello all. First of all, thanks to anybody who can provide some info. I have hot water heat in my house with three zones, all baseboard heat. The boiler is a typical set up with the pump on the return side and three actuators to control each zone. I completely removed one of the zones to install in floor heat. I installed the package, which came with a relay box and separate pump. The directions state that I run a jumper from the new relay box to the aquastat on the furnance to T and T to turn the boiler on. The problem I have now is when the the new thermostat calls for in floor heat it not only causes the furnace to fire up, it turns on the other pump on. The other zones are not calling for heat so this pump is trying to pull water through the system with the actuators closed. I am afraid it will burn up and it is obvioulsy wasting electricity. Is there a way of bipassing the other pump and still have the furnace fire up.

[paul52446m]

Well we will see what others have to say but here goes. If you have a relay with transformer
and aquastat on the boiler it would be very hard to separate the different powers to wire the way you are trying. Were you told that you have to have a separate pump to run your in floor heating? If you are going to run two pumps then you would use two relay boxes like the one that came with your in floor. If one pump would do the job then you could use another zone value on your in floor heat. Depending on how much water flow you need in your in floor you might have to go to a full flow value Regular 3/4 or 1" zone values only flow about 3-1/2 gal per min and full flows can flow 7 to 8 gal. per min.. If you decide to go with two relays, then each of the other two zone values can power up the relay which will start the pump and fire the T and T on the boiler relay. You should have a separate transformer to power the zone values. good luck Paul

[HayZee518]

any zone valves that I have wired get their input [opening-closing] off their respective thermostat or water temperature device [aquastat] 24 volts comes from the transformer, goes to the device, through its switch, then to the zone valve coil [or heater] TACO valves have a heater. When the coil heats up it actuates the valve body and closes an internal switch. This switch then turns on any auxillary equipment through a relay [pump, burner control etc] when the room heats up, the zone valve cuts off and shuts down the external device. TACO valves have a manual open lever on them.