Perform mini tune-up on heating unit to determine efficiency

Q. My heating system is 10 years old, and it heats well, but my utility bills seem high compared to the neighbors’. What can I do myself to make sure the furnace is running most efficiently?

A. Heating and cooling a home contribute the most to high utility bills for most families. Water heating is usually a home’s second-largest energy consumer.

Since central air-conditioning or a heat pump uses the same air handler (blower and ducts) as a furnace, maintaining a furnace for winter often also reduces cooling costs during summer.

Unless your furnace is actually malfunctioning in a significant way or making noise, you generally cannot tell whether or not it is operating at peak efficiency. If you try to compare your current utility bills to previous years, be sure to compare the actual amount of energy used in Btu, not just the dollar amounts of the bills. Energy rates always vary, so your current bills may be higher or lower, but you may actually be using the same amount of energy.

A simple annual do-it-yourself tuneup can help to keep your heating system running near its peak efficiency. Keep in mind, though, that if your furnace or heat pump is old, its peak efficiency may still be significantly lower than a new, stateof-the-art model. The newer units have variable heat output and efficient variable-speed blowers.

Also, don’t skip your regular scheduled professional maintenance calls just because you have done your own mini tuneup. There are many areas within a heating system that only a qualified technician can evaluate and adjust properly.

A rule of thumb when doing your own tune-up is that if you are not absolutely sure what some part or adjustment screw does, don’t touch it.

The first item to check is for safety. For a gas or propane furnace, put several drops of soapy water on all gas-line fittings. If any bubbles appear, there are gas leaks. Leave your house and call your gas company IMMEDIATELY to have the leak repaired. If possible, open a window near the furnace to allow the gas to escape.

Do a visual inspection of the electric-wire insulation leading to the furnace, especially at bends and near clamps. If you see any bad spots, switch off the circuit breaker first before checking the spots more carefully. Be sure to flip all the circuit breakers, because a heat pump or electric furnace uses 240-volt current through a double breaker. Better yet, switch off the main breaker to the entire house and use a flashlight to see while doing a closer inspection.

Check the accuracy of your wall thermostat. Many older thermostats are inaccurate, and you may actually be keeping your house warmer than you realize.

To test your thermostat, tape an outdoor bulb thermometer on the wall next to the thermostat. Set the thermostat at the desired temperature; then let the furnace start and notice the final temperature when the furnace kicks off. If the thermostat is inaccurate, replace it with an electronic setback model.

With the electric power still switched off, remove the heating unit’s side cover to gain access to the blower. Using a vacuum cleaner with a brush attachment, clean any dust deposits from the blower blades, motor and duct surfaces. If you see bearing oil cups, which some older blower motors have, put a drop of oil in each cup. Replace the cover, and make sure all the external cabinet screws are tight.

Even if you do not plan to remove the unit’s side cover for cleaning, check for loose cabinet screws. They must all be tight to avoid air leakage that can bypass the return duct system. At this time, clean the air-cleaner element or replace the filter. This is as important for keeping the inside of the heating system clean as it is for good indoor air quality.

Next, set the thermostat high enough that the furnace starts. Hold a thread tied to a stick near all the joints in the ductwork (both return and supply air ducts) to check for air leaks. If you find leaks, use either aluminum duct tape or black Gorilla duct tape to seal around the leaking joints.

This is also a good time to change your furnace filter or to clean a central air-cleaner element.

Q. I pulled the drywall off the walls in my house to add insulation. Since there is no insulation where the drywall is nailed to the studs, I thought about putting strips of R-4 bubble foil there. Will this help?

A. Putting strips of bubble foil there will not help much because the air will get squeezed out. Also, bubble foil gets its high insulation value partially from its reflective properties. When bubble foil is compressed between the stud and the drywall, this is less effective.

Uncompressed sheets of bubble foil can be very effective insulation, particularly at blocking outdoor heat on hot summer days. It is more effective when there is an open gap around it.

Send inquiries to James Dulley, Arkansas Democrat-Gazette, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www. dulley.com.