At the thermostat
Set the thermostat more than 5° F above room temperature and see whether the heat goes on. If you have an automatic day-night thermostat, make sure that the cycle hasn’t been reversed. According to the Sparta heating professionals,, if your thermostat’s contact points are exposed to air, they may need an occasional cleaning. First, turn off the power, then carefully remove the cover. Lower the setting to open the contact points, then run a business card between them. Raise the setting to close the points, then repeat the cleaning procedure. Replace the cover and restore power.
To clean the contact points of certain round thermostats, first turn off the power, then remove the temperature-setting dial. Wipe the points with a cotton swab dipped in a 50-50 vinegar-water solution.
On your way to the furnace or boiler
Check for a blown fuse or a tripped circuit breaker, says the reliable Sparta plumber. If you have a remote emergency switch, make sure it isn’t turned off. If you have an oil burner, check the fuel gauge on the oil tank; if there’s no gauge, remove the cap of the tank-filler pipe and check the oil level with a stick.
At the furnace or boiler
Check the emergency switch to make sure it isn’t off. If you have an oil burner, press the overload reset button the motor housing then push the stack-control relay switch (located on the flue or on the burner housing). If your oil burner is controlled by a photoelectric cell, this “seeing eye” cell could be dirty, preventing the unit from operating. First turn off the emergency switch, then unscrew the transformer from the fan housing and flip it over. You will find the photoelectric cell on the underside of the transformer or on the housing. Gently wipe it with a clean cloth.
Lastly, if you have a gas burner, make sure the pilot light is on. If it isn’t, relight it according to instructions in the owner’s manual or on the plate mounted on the unit. If the pilot light won’t stay lit, have your local Sparta heating service technician check the thermocouple. If your system runs but delivers inadequate heat, some of the possibilities would be to inspect either your hot-water system, steam system or the warm-air system, whichever is relevant to your home.