[Pluto]

The fan for the bedroom heat is not coming on and I've narrowed it down  to the thermostat being the problem.  

The fan works just fine when I jump the 12v+ wire to the heat output on the back of the thermostat, so for whatever reason the original thermostat is not sending the needed voltage to the heater fan.

Since the thermostat controls both compressors on the AC and the heat I'm not sure what I can replace it with.  

Has anyone replaced the original PSG thermostat with another model that will work with our AC and the heat?

Thanks 
Tyler

[cwl1979]

The fan for the bedroom heat is not coming on and I've narrowed it down  to the thermostat being the problem.  

The fan works just fine when I jump the 12v+ wire to the heat output on the back of the thermostat, so for whatever reason the original thermostat is not sending the needed voltage to the heater fan.

Since the thermostat controls both compressors on the AC and the heat I'm not sure what I can replace it with.  

Has anyone replaced the original PSG thermostat with another model that will work with our AC and the heat?

Thanks 
Tyler

Check the relays on the aquahot. Mine were bad so I changed them both and everything worked again.

[Richard]

https://newellgurus.com/showthread.php?t...thermostat

Link to the Coleman Tstat that is a drop in contained in this thread

If you go this route, the two freeze protect wires on the tstat are tied together.

[Pluto]

Excellent, thanks Richard. From the pictures of the thermostat it looks like the freeze protection wires are on the thermostat harness. Are those what need wired together?

[Richard]

Yes,

[Pluto]

I was wrong in my original statement, when I said that jumping the 12v+ wire to the heat output on the back ot the thermostat would run the heater.

The aquahot is actually looking for a ground connection and not a 12v+. I'm not real savvy with this, but if I use a jumper wire to complete a ground connection from the terminal strip on the aquahot, the corresponding zone relay on the aquahot, or the back side of the interior thermostat both the zone pump and blower motors will start up.

It seems odd that both the bedroom thermostat and now the living room thermostat has quit completing the ground needed to run the heat inside.

We were holding off on replacing the bedroom thermostat because it still runs the a/c and between the bathroom and living room heat we stayed plenty warm, not to mention the replacement is around $200. But, now that the living room thermostat has quit also we are going to replace both of them.

Is it a common issue for these thermostats to quit like that? I guess they are 27 years old though, so it's bound to happen.

[Richard]

I’m in a time crunch right now and I will find the thread and draw you a picture later today.

The Newell setup with the AH uses a standard automotive relay to take the 12V pos from the tstat as the trigger and close a ground circuit through the relay contacts. Buffaloed the heck out of me some years ago.

[Pluto]

Haha well I guess I'm wrong again (nobody ever listen to me). I've messed with this so many times and I just don't understand what's happening, obviously.

It seems like it would be straight forward, but my simpleton brain just isn't computing.

[Pluto]

I've been talking to a guy at work about this because I'm not really understanding the concept. But it's starting to make some sense I think. If the thermostat isn't switching to ground, but is instead sending out a 12v+ when heat is called for, then that 12v+ is causing the relay to connect the ground.

I really struggle with this stuff which sucks because its the one area I am the most interested in understanding. I've always found the electrical side of systems to be the most fascinating element but I'm just too dumb to get it.

A drawing would be really helpful, Richard and I would appreciate it greatly!

Igor must have grabbed me the Abby normal brain lol

[Pluto]

Got the front thermostat to work with the heat! Your message helped it click for me, thanks Richard.