If your furnace is balky, you have a problem you should address right away. However, before you buy parts or call for service, there are a handful of troubleshooting tips that may help you identify what the issue is.

• Listen: Set the thermostat high and listen for noises. Does the furnace come on at all? Does it quickly shut off again? Does it run but produce no heat? If it suddenly runs properly, then you probably just had your thermostat set too low.
• Not starting: If it isn’t turning on at all, first check the fuse box and the circuit breaker. If all the breakers are in order, see if the furnace’s pilot light has gone out. If the pilot light is still lit, the issue might be a broken thermostat.
• Stopping and starting: Check the condensate reservoir, if your model has one. If the reservoir is full, see if there’s an obstruction in the drain, because the reservoir should drain before it fills. If you can’t find a clog, then the pump might be broken. If the reservoir is not full, or if there is no reservoir, look inside the case for signs of dirt that could be clogging the air intake. If you can’t hear the blower motor running, then this is likely the problem. If it makes a lot of noise, then it may have a problem with excess pressure. If none of these issues are the source of the problem, you probably have a broken heat sensor.
• Starting without producing heat: Check that the gas valve is on. If it is, check the vents for obstructions. If there are none, make sure the igniter glows when the furnace turns on.

For more professional advice about furnace issues and other HVAC topics, contact the pros at Smoky Mountain Heating & Air. We serve the HVAC needs of Asheville area homeowners.

Our goal is to help educate our customers in Asheville, North Carolina and surrounding areas about energy and home comfort issues (specific to HVAC systems).

Image courtesy of Shutterstock