Honeywell zone valve won't close switch to activate heat
Our hydronic heat system is working fine for one zone only. The second zone will only switch on 30% of the time that the thermostat actually makes its call. In order to make that zone work, we have to cycle the power on and off to the board by flicking the power switch.
We have replaced the zone control module circuit board, thinking there was a short somewhere. No change.
We have replaced the valve, thinking that it was faulty. No change.
We have replaced the wiring that leads from the valve to the zone control module thinking there is a fault there. No change.
We have doubled up on the low voltage wire for the 'close' end switch, thinking there is a loss of voltage over the run. No change.
We can't seem to find any repair company that can fix it and we have spent hundreds of dollars chasing down the problem.
The call is made and only answered sporadically on that problem zone. Meanwhile, our other zone is functioning perfectly off the same board and the same equipment.
Any suggestions would be greatly appreciated.