My gas furnace comes on at 4° below the set temperature on the thermostat. Is this a thermostat issue?


If it's always been this way, then it may just be an old stat and not very accurate anymore so you may want to replace it. If not and your stat is newer, then it's faulty, and they should give you a new one.

Updated on February 3, 2018

Original Article:

How to Figure Out What is Wrong With Your Furnace
By Dan Robbins