DIY Furnace Maintenance

Heating and cooling costs account for around 48% of the energy used in the average home. With spiraling energy costs and more home owners wanting to live sustainably, one of the best ways to reduce your winter hydro bill is to maintain your furnace and ducting.

Leaky Ducts

Check you ductwork for leaks as you lose about 20-30% of heated air through gaps in your ducting. Check for leaks with a duct leakage tester and focus on those areas where ductwork is exposed as it may be costly to reach hidden ducting.

When leaks are located, clean ducting, wrap the area with foil tape and press down to ensure that it is properly adhered. Use mastic on leaks which are smaller than ¼-inch. Paint mastic over the foil tape until it is about as thick as a nickel.

Furnace Maintenance

Start with a visual inspection of the furnace. Turn off the heat and fuel supply which can be found at the top or bottom of the basement stairs or on the wall behind the furnace. The fuel shut-off valve can be found on the gas line located near the oil tank.

Remove the combustion chamber door and burner cover if you model has one. This will be held in place with a couple of screws. Soot buildup on the combustion chamber walls can cause corrosion. Scrape off soot with a small wire brush. Now use a vacuum cleaner to remove and dust and debris from the unit. See here for particular details.

Open the blower door and vacuum the blower compartment.

Clean the blower blades but be careful not to disturb the wiring or counterweights as this could throw the blades off balance.

Use an emery cloth to clean the sensor of residue.

If you have an older furnace, you will have to oil the motor and blower-shaft bearings. Remove the oil caps and apply 2-3 drops of lightweight machine oil. Do not over-lubricate.  Replace the caps.

Remove the air handler cover and check the blower belt for cracks. Check that the belt is tight—it shouldn’t move more than ¾-inches when you press against it. You can replace the belt or tighten it by moving the motor back a bit. Just loosen the motor mounts and move the motor back, then tighten the mounts again.

Check the outside flue is clear of ice, snow and vegetation.

Clean out or replace the air filters according to the manufacturer’s guidelines (some of these need to be cleaned every month).

If you are unsure or uncomfortable with any of these steps, its best to call a pro in. Regular maintenance will keep your furnace running at its most efficient.