Originally Posted By: BBOWMAN This post was automatically imported from our archived forum.
Hubby cut power- took off olf thermostat for A/C to put on a programmable one and no power. So he took that one of and putthe old one one and still no power to Thermomstat/ the LCD display will not light up and no A/C. What did the old fool do wrong?
Originally Posted By: jsavino This post was automatically imported from our archived forum.
Did hubby install the batteries? They do have a battery back-up for the programing. If the LED’s are not lit the thermostat may be defective.
Some thermostats are not compatible with certain types of heating and a/c systems. Oil fired and gas systems require a different thermostat than a heat pump or electric heat.
It's very possible he blew the circuit board (if equipped) or a broken wire to the a/c unit.
-- John Savino
HomeWorks Inspection Services, LLC
St. James, NY
631.379.4241
Originally Posted By: dedwards This post was automatically imported from our archived forum.
Go to the thermostat and select FAN (not Auto). That will tell you immediately if you have power (24 volts AC) coming to the thermostat. If the fan does not run then you will need to call the repairman because it will require someone to troubleshoot it further. There are too many variables / possibilities to walk someone through. You did not say if it was a heat pump or a standard AC unit. Typically there is a “reset button” on the outside unit if its a heat pump. Reset the circuit breaker too in case it has been sitting for a long time. There may be some corrosion on the internal contacts. Any other troubleshooting is best left to a professional.