[tyler2you]

I have a Lennox unit that cools the second floor of my home and the digital control is by Honeywell. It seems to be not getting power. I checked the breakers and they are not thrown and then I turned them all off and back on and still nothing. What else can I try?

[mygirlsdad77]

Need more info, is it just the outside unit not coming on, or the outside unit and indoor blower both don't come on. Is thermostat dead. You will need to check for 120v to airhandler(furnace or strictly air handler). If you have power there, then you need to check for 24v at board.

[tyler2you]

Everything is dead. Nothing comes on. I took off the thermostat and tried to croos touch the wires to start it, but nothing happened.

[hvac1000]

You could have a
Bad fuse located in the inside unit
Defective low voltage transformer
Bad blower door switch or the door was not replaced properly causing the switch not to close.
Defective power supply to the indoor unit
BUT whatever you do leave the thermostat replacement alone until you find the problem. It seems almost everyone wants to replace the thermostat first without checking for the real problem. If you are good with a testing meter you should be able to track the problem down if not call for ON SITE service.

[HVACtechsnj]

hvac1000 once again is correct on this issue. It seems he has many years in the field and very very knowledgeable. It seems with all these tstat issues on this board we need to see if "Before replacing a thermostat" on the main page. Many times it seems as though the wrong stat is being purchased, wires are not being labeled and most important power is not being turned off which we all know can cause several more costly repairs.

[hvac1000]

99% of the people never read the Sticky notes. Lol