Annual tune-up keeps heating system running efficiently
Q: My heating system is 10 years old and heats well, but my utility bills seem high compared to neighbors. What can I do myself to make sure it is running most efficiently?
A: Heating and cooling a home contribute the most to high utility bills for most families. Water heating usually is the 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 if it is operating at peak efficiency or not. If you try to compare your current utility bills to previous years, make 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 actually are using the same amount of energy.
A simple annual do-ityourself tune-up can help to keep your heating system running near its peak efficiency. Keep in mind, though, if your furnace or heat pump is old, its peak efficiency may still be significantly lower than a new, state-of-the-art model. The new ones 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, 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 them more carefully. Make sure to get 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.
Check the accuracy of the wall thermostat. Many older ones are inaccurate and you may actually be keeping your house warmer than you realize. Tape an outdoor bulb thermometer on the wall next to it. Set the thermostat at a temperature, let the furnace start and notice the final temperature. If the thermostat is inaccurate, replace it with an electronic setback model.
With the electric power still switched off, remove the unit’s side cover to gain access to the blower. Using a vacuum cleaner brush attachment, clean any dust deposits off 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 side cover for cleaning, check for loose cabinet screws. They all must be tight to avoid air leakage which 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.
Set up the thermostat so 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 around the leaking joints. This also is a good time to change your furnace filter or clean a central air cleaner element.
Q: I pulled the drywall off the walls 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. The air will get squeezed out. Bubble foil also gets its high insulation value partially from its reflective properties. When it 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.