HVAC Questions? Ask an HVAC Expert for Answers ASAP
Hello, your programmable thermostat is wireless, but it's not Wi-Fi.When you say it's not responding, which buttons are you pressing, and what's shown on the display?When you say a PCB has been replaced, where was the PCB?
It seems likely that the power to the thermostat transceiver was off while the boiler PCB was being replaced. That might have cause a problem. Firstly, I would remove the batteries from the CM727 for ten minutes, then insert them and try again. If still no good, have a look at the Honeywell Binding / Rebinding Procedure:https://heatingcontrols.honeywellhome.com/Documents/Installation-Guide/pdf/1066.pdf