Thermostat Manuals
Most thermostats have a differential field on them of 5 degrees, that is non adjustable. The reason for this is so the furnace does not burn
itself out by cycling on and off trying to keep the the temperature you desire. If you have the old fashion round honeywell mercury type thermostat, you may want to adjust the preheat element on it. Take off the cover and there is a plate near the bulb with decimal numbers on it that have to match the ampere rating of the oil burner or gas burner, so make sure this is done.
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