"Ashton Crusher" wrote in message
...
I"ve got two AC units for my house. The outside part of this split
system houses both AC compressors (It's a Freus water cooled unit) in
one enclosure but they have separate Fused feeds. Inside the house
there are two completely separate air handlers. Each system has it's
own thermostat. In the past week both thermostats have started acting
funny. The backlights for them come on and then fade out or "stutter"
out and the LCD digits fade away and can't be seen whether the
backlight is on or off. This happens about 2 seconds after you press
the buttons to raise or lower the temperature or the button to turn on
the backlight. I thought each thermostat was powered by a transformer
in each of the air handlers. That's how the original system with two
completely separate Carrier AC units was set up. The thermostats are
Braebun brand. Has anyone seen these thermostats go bad this way or
should I be looking at some electric issue in the AC unit? Seems
quite a coincidence both thermostats started doing this at the same
time if it's a problem with the thermostats.

I would assume they have batteries in them. Check that out. WW