AC and furnace not working

Old 06-29-16, 06:02 PM
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AC and furnace not working

This past winter a builder moved my thermostat to another room as part of a remodel. The furnace worked fine. Now I try to put on the AC and it doesn't work. Neither does the furnace.

The circuit breaker didn't pop so I assume it is not an electrical problem. The thermostat shows the current temperature and shows the desired temperature when I adjust the settings. Any ideas?
Old 06-29-16, 06:10 PM
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I'm guessing that you lost the 24VAC to the thermostat. The 24VAC comes into the thermostat on the R terminal. With the thermostat off, measure the voltage from terminal R to the C terminal (if present). If you don't have a wire on the C terminal (not all thermostats do), measure from R to the Y terminal. You should measure ~24VAC. If it reads 0V, check the furnace control board for a fuse. Many boards have a fuse for the 24VAC transformer so if a short occurs, the fuse will blow rather than wipe out the transformer. Report back your findings.

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