[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.