Hi Everyone-

We've recently purchased a home and have ran into some interesting issues with the HVAC that I was hoping to gain some insight to.

Our home has two systems one for upstairs one for down. Both units are on the roof and are "combined" units. (a/c and furnace). The make of these are Trane.

The thermostat wires available are (Green (G), Blue(C), Red(Rc/R), White(W1), Yellow(Y1).

We recently started having an issue where the upstairs thermostat stops receiving power pretty much daily. At about 5pm the volts to the R wire go from 26v to 1.2v. Then at 11am the following day it comes back. I've been monitoring this for 3 days now and it has been consistent each day.

I don't believe there is any kind of timer, nor know why there would be?

Thoughts?

Thanks in advance

Jesse