Diagnostics

Diagnostics

The gas furnace is an appliance looking like a large box that does the following:

  • takes in cold air,
  • cleans it with an air filter,
  • heats it up with a gas burner using a heat exchanger,
  • distributes the warm air with a blower motor through your home's ductwork

The heated air then cools down in your home's various rooms and returns to the furnace through return air grills and ductwork.

The cold returning air enters back through the air filter into the furnace to complete another heating loop. Sometimes there is a humidifier mounted on the furnace or the return air ductwork. Furnaces come in different efficiencies measured in AFUE.

Once in a while things don't work quite right and you need to troubleshoot a gas furnace repair or relight a standing pilot if it has one. Most newer furnaces have electronic ignitions and need special troubleshooting.

Gas Furnace Produces No Heat
Possible Causes

  • Thermostat set too low and not calling for heat
  • Thermostat not working
  • Circuit breaker or fuse controlling the furnace is tripped or blown
  • Natural gas or propane control valve is closed
  • Pilot light is out

Gas Furnace Does Not Produce Enough Heat
Possible Causes

  • Dirty furnace air filter
  • Gas burners may be dirty or need adjustment

Gas Furnace Comes On and Off Too Frequently
Possible Causes

  • Dirty furnace air filter
  • Blower motor problem
  • Thermostat problem

We always recommend yearly maintenance by licensed service technician to make sure your heating and cooling system is running at its maximum performance.

Please contact us at 416-274-3583 or go to our contact us page to submit a contact request form.