[Pluto]

Now that it's getting cold here in AZ it's time for us to start running the furnace.  Zone B is working as it should but neither zone A or C is working.

 Neither the heat exchanger fans or associated pumps for A and C is coming on. I've moved the relay from B to A to see if that would do anything but it did not.

I'm now going through the manual and trying to figure out the problem.  In the manual it's telling me to check for a ground signal from the thermostat at pin 0, however it doesn't show me where pin 0 is.

Where would I find pin 0 and how do I check for a ground signal.

Thanks in advance

Tyler Phillips

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Also, it's kinda strange that the one zone that is working doesn't have a wire going to it from the thermostat.

[Trainer]

Tyler. Call me. Rudy Legett
7 one 3. 8 one 8. 3234

[Pluto]

I was able to get the front heat working. There was a loose wire on the relay for the front thermostat that was preventing it from switching. I still haven't figured out the problem for the bedroom heat.

Both zones will come on when I made a connection from the respective terminal to ground. So it has something to do with that. I replaced the relay for the bedroom but it didn't make a difference.

It's supposed to get pretty cold the next couple of days but we should be fine with the front heat going.

[Trainer]

Someone tell Tyler to read the forum and call me. NO call NO help!!

It is still 30 minutes till 8 pm central.

[Richard]

Tyler,

Good troubleshooting so far. Now that you know a ground signal will start the intended zones. And you know the purpose of the relay is to convert the 12V pos signal from the tstat into a ground signal that the AH is looking for.

Confirm you are getting a a 12V signal from the tstat at the relay terminal.
Confirm the relay is wired correctly, when it is triggered the contacts should make to ground.