Blank LCD Thermostat Display

[smworth]

The display on the LCD thermostat is blank and the Air Conditioning will not come on. Any thoughts where to start looking for the problem?

[htrguy]

Secondary drain saftey cutout switch on the evaporator drain I.E. clogged water drain.

[smworth]

Thanks, is it a float type switch and where is it normally located?

[smokin68]

Does your t-stat take batteries? Time for the yearly clean and check.You have no low voltage if stat doesn't take batteries. Call for service.

[htrguy]

Originally posted by smworth
Thanks, is it a float type switch and where is it normally located?

Already told you, on the evaporator. Look for water drain pipes. If you can't find those you're in over your head.

Before all chime in and say it's not a DIY site, this may only be a clogged drain. If it's not then a tech will be needed to figure out why the control voltage is not there.

[smworth]

OK Guys, I found a blown 3 amp fuse on the main circuit board. I also found a short in the 24 volt feed to the compressor relay. It looks like it shorted from the vibration of the unit ( inside the junction box).

All's well. Thanks again for your help.