I have a carrier debonair 450 it is blank and not working it does not take batteries. needing help

Press mode and program together and hold to enter configuration. Press mode until option 11. 11 is the run time before reminder, put this to 0.

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This is most likely the flame sensor in the actual furnace and not the thermostat. Post the model of the furnace.

The t-stat needs a common and a hot. I know that is simple but it doesn't hurt to ask. Do you have the 24 volts needed to operate the t-stat? If you have 18 volts that may affect the lights.

Does it have a battery backup in the unit? If so replace them. If its an older model used frequently oil from your hands gets behind the buttons which causes intermittent connections and can cause display error. Remove the unit, carefully open it up and clean all contact surfaces with q-tip and a bit of rubbing alcohol. May solve your problem. While your at it make sure all wire connections are tight. Mark all wire locations during disassembly to make sure they go back in the right place.

Hello my name is Willie of GMP mechanical services out of Centreville Virginia. I need some more Information about your AC unit is electric or gas heat. Is there a fault or fail signal in the digital display anywhere?

Hello, sometimes this happens when the condensate overflow switch trips duento a clogged condensate line. You need to find the outlet of the condensate pipe and use a wet/dry vac to clean it out. The pipe will be 3/4 inch PVC. Let me know what you find. If the drain is clear then the problem could be related to a burned out transformer or dead batteries if the thermostat uses batteries.

if it has no batt I would ck transformer for 24to26 volts no voltage replece transformer be sure trans has 115 volts to it trans should be in furnace section

Check voltage at unit. Also check the 5 amp fuse in the unit. If this unit has a float switch in the drain line check that. Rus

Check the battery in the thermostat it is dead!! Should be 2 AA batterys!

please check there is power comes to the thermostat first.