A poorly heating furnace is just as frustrating as one that fails to work at all. Not only are you stuck with a chilly house, you may also be stuck with high energy bills for minimal heat due to the malfunction. The following guide can help you troubleshoot the cause of the poor heating so you can have the problem repaired as soon as possible.
Check Thermostat Settings
Poor heating is often a thermostat problem and not a furnace issue at all. First, check that the furnace is set to "heat" or "auto" rather than to the "fan" setting. If the fan is on, then it will blow air constantly, even when the furnace isn't running, which can result in cool drafts. Another issue can be with the thermostat calibration. If the thermostat is no longer properly calibrated, the temperature it is set to won't accurately reflect the temperature that the furnace provides. You may have to turn up a poorly calibrated thermostat to get to the desired lower temperature. Your HVAC tech can check calibration and function and then make any necessary adjustments to remedy the problem.
Don't Trip the Switch
There is a switch inside your furnace called the "high limit switch." If this switch is tripped off, your furnace may operate the fan, but there will be no warm air coming out. Lack of airflow into the furnace is what typically trips this switch. Often, the furnace filter is to blame, which is a simple replacement that you can do yourself. Use a long-handled duster or narrow broom to remove any dirt built up in the filter housing, as well. If this doesn't work, you may need to schedule a full tune-up and cleaning. Your tech can locate the cause of the blocked air flow, repair it, and then reset the limit switch so everything works as it should again.
Maintain the Burner and Pilot Assembly
A poorly functioning pilot light and burner can lead to colder than expected air. Your pilot light should remain lit and burn with a steady blue flame. A flickering yellow or orange flame or a pilot light that constantly needs to be re-lit indicates issues. Often, the problem is as simple as a dirty pilot valve or burner assembly. Your furnace tech will make sure everything is clean and in working order. If there is a malfunctioning component, a part replacement will typically solve the issue.
Contact a furnace repair service for more help with your HVAC issues.