A DIYer’s Guide to Heating Repair
Heating repair can be a simple fix like a flip of a switch or it could require the help of a professional. Check out our DIYer’s guide to heating repair.
Test the High-limit Switch
Repair experts tell us that they often show up at a residence only to find that the unit isn’t getting power because of a tripped breaker or a flipped switch. So check that first. Flip the switch on the side of your furnace, and flip the breaker off and on again before you even think about replacing any parts.
Never Changing the Furnace Filter
Install the New Igniter
Most high-efficiency furnaces use a “hot surface” igniter that heats up to 1,800 degrees F to light the burners. Once lit, the burners then heat a flame sensor. The furnace’s computer uses the signal from the flame sensor to confirm a successful ignition and turn off the igniter. However, over time, the constant heat/cool cycles cause the igniter to crack and fail. And the flame sensor can develop surface corrosion, causing it to send an incorrect signal to the computer. Or it can simply wear out.
The igniter can be held in place either by screws or by a snap-clip arrangement. Use a lighted flexible mirror to discover the method used on your furnace. Then remove the screws or unsnap the retainer and remove the old igniter. Use care when you install the new igniter—it’s brittle and can crack or shatter easily.
Next, remove the flame sensor. If the sensor element is covered with corrosion and you don’t mind replacing the sensor later, you can try cleaning it. Otherwise, just replace it.
Clear the Pressure Switch Tubing
Condensing gas furnaces attain their efficiency by extracting water from the exhaust gases. Sometimes condensation from that exhaust can form in the pressure switch tubing. This silicone tubing runs between the flue and the heat exchanger and the safety furnace pressure switch. Experts tell us they usually remove those tubes and blow them out with compressed air as a preventive measure.
Check Shutoff Switches and Breakers
Make Sure the Chimney Exhaust Flue is Clear
Flush out Drain Lines
Find out how to drain the furnace lines in more detail.
Adjust the Dampers
Check the Intake and Exhaust Pipes
Look for Blocked or Leaky Ducts That can Restrict Airflow
Also check for handles protruding from the ductwork. These are dampers or air conditioner bypasses—make sure they’re open.