Hi- I have a what I reckon is a simple HVAC setup. One Weil-Mclain Gas Boiler in turn providing steam heat to my radiators on the first and second floor. previously my nest learning thermostat 3rd generation was working quite well however I've recently ran into trouble.
Given my boiler was 30 years old I had it replaced with a new Weil-Mclain Gas Boiler. The new one looks quite similar to the old one except it has a few automated controls one of which is an automatic vent dampener. For the past few days there was a loud buzzing sound coming from my boiler room and upon investigation it seems the motor from the vent dampener was constantly running. I called my hvac guy who investigated and determined that my nest was causing the issue as it was sending some sort of voltage to the vent dampener keeping it on. He then stated I have no option but to replace the Nest with a simple non smart thermostat. I also don't have a C Wire Installed. Is this correct/can someone chime in if they've experienced something like this before? Apparently according to federal law all gas boilers now come with a vent dampener for efficiency purposes so I cant have the piece removed.
What model do you have?
How is it wired? Post a picture of the Nest wiring and the wiring at the boiler.
The majority of boilers are just looking for a simple switch closure (like a light switch) and you then need to use a simple relay circuit to connect the Nest.
This is a sample circuit that I know works. Don't mind the labels as I made a mistake when drawing this up and haven't been able to fix it. For the Learning Thermostat use R = Rh amd W = W1.
Appreciate your help again here, Patrick_Caezza.
teni94, I'm chiming in to ensure you're all good here. Have you seen Patrick's response above. If you still need help here, kindly provide the answers to his questions above so we could keep the ball rolling.
We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.