View Full Version : Wiring 101

11-13-2007, 01:01 PM
Home has forced hot water heating system via hot water furnace.

Contractor installed 200 gallon hot water storage tank (7 daughters) and (1) new circulating pump and zone to operate the new hot water storage system.

The two original forced hot water heating zones, first floor, second floor used to worked independantly, but now work together.

If the upstairs thermostat calls for heat at 72 degrees, and the downstairs thermostat calls for heat at 60 degrees both heating zones come on at the same time.

Massachusetts' heating code calls for flu monitor and vent fan to be wired to each zone to insure proper exhaust venting.

I called a HVAC to fix system but he could not figure the wiring out and has not returned.


MLT Hand

11-13-2007, 03:08 PM
You need a 3-zone controller, and may not have it. Think of the water heater as a separate zone. It is often set up as a priority zone which means that the house heat won't come on if the WH needs heat. There are add-on controllers that could be used which would allow three separate thermostats to control the three pumps. www.taco-hvac.com (http://www.taco-hvac.com) has one that would work as seen in this catalog http://www.taco-hvac.com/uploads/FileLibrary/100-5.0.pdf. That's what I have in my house. One zone for the indirect, one for the radiant heat, and one for the air handler. Some boilers can do this with their existing controller, or may support an add-in board. If it can't, then the Taco unit, or one like it, would work.