I have two plinth heaters on either side of my kitchen island. Since the rest of the house is hydronic, I presume that these are hydronic (there is a zone valve at the boiler) with electric fans because they have fan speed switches and not much heat comes out unless these are on.

I have just tried to replace the existing thermostat with a Honeywell RTH2300. I barely use this zone so I went with something easy. However even though the wires are hooked up the same way (G Y W Rh Rc) and set the temp to engage, nothing happens. The fans don't even turn on. The thermostat looks like it is engaged but the fans don't come on. One unique thing I have never seen before is that this thermostat has a switch that says gas/oil and electric. My system fits both descriptions (ie I have a gas run boiler but I have a G wire to allow the thermostat to call the fans when it calls for heat).

I have tried both switch settings with no results. Could this thermostat not be compatible with this heat zone?

  • Can you trace the wires that control the zone valve on that heat zone? – ThreePhaseEel Feb 3 '19 at 0:06

Stupid me. The fan has a delay of a few minutes after the thermostat calls for heat. I set it to gas and called for heat and waited 10 or so minutes and the fan came on.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.