Trouble with home A/C unit anybody work on them that might have advise

[Simplysmn]

Hey guy's anyone know anything about a roof a/c unit it has power to it but Nothing to thermostat and unit will not turn on . Problem is I can't get up on the roof due to bad knee's can't climb ladder so I have my son that has checked for power but we can't find the problem . Any Idea's Unit is less then 5 yr's old I just hope it's still under warr. ????

 

[Hoefler]

If it is that new, you may have a digital thermostat. If it does, does it have batteriers??Replace the batteries. If not, the transformer is not sending power to the stat. Check it for voltage on both sides, 110 in, 24v a/c out.

 

[Simplysmn]

would the transformer be in the unit or attic ? and can you give me a idea what I need to have him look 4 ? Thank you for the help . if this will help it's a Lennox unit model #12gcs042x-100-spb I am in the process of doing more investagation

 

[Hoefler]

The transformer is usually in the main unit. It could be a separate unit or integrated into the board.

 

[Skydiver]

Can't do much trouble shooting from here. I have some AC experence from many years ago, including tech school. My central did the same thing. Turned out to be the little control box that prevents the compressor from being cycled on then off more that every 5 minutes. Can't remember what it is called right now. It is in the controll side of the wiring, not the main power side. If the contactor coil is energizing it should make a slight hum. Sounds like your problem is on the control side.
You have to use a volt meter to find out what is failing. What sounds are you hearing when the system is turned on,,,any?
BE careful.

 

[Simplysmn]

Hey Guy's Thank's for the help but we got it fixed it was a combo of a fuse and a bad thermostate