I searched for this topic, and while a few similar questions came up, none of the responses appear to work for me. I have a 30-year old Peerless boiler with 3 zones. In order to add a Ecobee thermostats, I have to add a common wire to all zones.
The thermostat relay (an Argo AR821-T) has a 24V transformer, and measuring between T and P (red wire and the closest P terminal) I get ~30V. When I hook up a wire and feed it to the C terminal on my thermostat however, nothing happens. I tried attaching it to the other P terminal as well, which makes no difference. What am I missing?
The thermostat relay (an Argo AR821-T) has a 24V transformer, and measuring between T and P (red wire and the closest P terminal) I get ~30V. When I hook up a wire and feed it to the C terminal on my thermostat however, nothing happens. I tried attaching it to the other P terminal as well, which makes no difference. What am I missing?