Maintenance for the HVAC

A little preventive maintenance can go a long way.

Most homeowners have a rudimentary understanding of their heating and air-conditioning system but only get “up close and personal” with the equipment when a problem arises. And when a problem arises with the HVAC system, the house can get very hot or very cool very fast, which can elevate the inconvenience to an emergency. However, like most other components of your home, a little preventive maintenance can help avert catastrophic failures in the future.

Since HVAC systems often mystify the homeowner, consulting a professional technician is typically a good idea. Pro technicians will check system functions, safety controls and adjust the operating sequence where appropriate. They should inspect the electrical components and connections and repair/replace or tighten any components as required. They’ll inspect pumps, lubricate and check flow rates where appropriate; clean and lubricate motors as required; examine belts, and adjust and align them as required. A professional HVAC tech will also inspect, clean and balance the blowers as required.

A service visit in the spring should entail cleaning inside the air conditioner coil, condensate pans, condensate traps, and condensate lines to prevent obstructions. The outside coil should be cleaned and fins straightened for efficient operation. The tech should check refrigerant levels and if low, find the leak and fix it. (According to many equipment manufacturers, a 10-percent refrigerant loss will result in a 20-percent decrease in system efficiency.)

HVAC service in the fall should include cleaning the furnace’s burner assembly and removing soot from the fire side of the burner. The heat exchanger should also be inspected for cracks. A professional tech can adjust the air-to-fuel ratio of the burner and perform a combustion analysis.

Some professional service techs will suggest having your system inspected up to four times a year (of course, they’re the folks that are selling the service). However, an annual inspection from a knowledgeable pro is a good investment by the homeowner.

Following are also some simple maintenance steps a DIY’er can take until time for the next pro inspection.

Shown is the Bearcat wood-burning furnace from Charmaster.
Shown is the Bearcat wood-burning furnace from Charmaster.

Filters & Ductwork

Be diligent about regularly replacing the filters that remove dust and other particulate impurities from the air as it circulates through the HVAC system. Most systems use disposable filters. Some furnaces have an electrostatic filter, which is a sturdy metal filter that needs to be cleaned every few months. In either case, a clogged filter hinders airflow, and your system will have to work harder to achieve the temperature programmed in your thermostat, which wastes both energy and money.

The ductwork in HVAC systems should be maintained as well. Some homeowners opt for having ducts professionally cleaned with high-pressure vacuum equipment. Duct-cleaning won’t noticeably improve energy efficiency, but there may be other benefits such as the removal of dust, mold and other allergens.

Make certain that duct joints are sealed to get the most efficiency from your system. Avoid “duct” tape for air ducts and wrap the joints with high-quality foil-faced tape, which is more durable and creates a tighter seal. In warm climates, ducts that run through attics should be sealed very tightly.

Also, keep the area around the furnace clutter-free. Basements and utility rooms, which often house the furnace, tend to accumulate all sorts of junk and storage items, but a furnace needs good airflow for proper operation. It’s best to keep the area around the equipment clear of obstructions and especially combustible items.

Maintaining the Fan Motor

Many furnaces have factory-sealed bearings that never need oiling, but other motors do require occasional lubrication. Remove the access panel and examine the blower motor. If it needs oiling, then you’ll find small holes at either end of the motor.

Apply a couple of drops of oil (usually 10W/non-detergent) to lubricate the motor.

Not all fans run off a belt, but if it does then it may periodically require tightening. Check the tension by pushing down on the belt midway between the fan and the motor. The belt should flex about one inch. If it doesn’t flex appropriately, then loosen the nut on the bracket that holds the motor. Turn the second nut to tighten or loosen the belt. Retighten the nuts once the belt has been properly tensioned. Cracked or stretched belts should be completely replaced.

Use foil tape for an air-tight seal around duct work.
Use foil tape for an air-tight seal around duct work.

A belt-driven fan motor will operate most quietly and efficiently when the pulleys are in line with each other. Place a straight edge, such as a level or ruler, against the sides of the pulleys on the motor and the fan. Check for any deflection as evidenced by a triangular space between one of the pulleys and the straightedge, which indicates misalignment.

To correct this, loosen the bolts that hold the motor on the mounting bar. The bolts of the motor are held in slotted bolt holes.

Slide the motor along the bar until the pulleys are aligned and retighten the fasteners.


Side Note 1

Safety Tips for Wood-burning Furnaces

Do you heat your home with a wood-burning furnace? The most important item to remember about operating and maintaining any brand of wood-burning furnace in your home is safety. You can never be too careful. Read your operator’s manual for proper installation, operation and maintenance. Establish a routine for proper wood storage, maintenance of the furnace and safe firing techniques. Also, have a clearly understood plan to handle a chimney fire, should one occur.

The experts at Charmaster ( offer the following monthly maintenance tips for your wood-burning furnace.

Remove and clean creosote from stove pipes between the furnace and the chimney. Install new stove pipe as needed for safety.

Clean creosote from the heat exchanger.

Check and clean creosote in the chimney and chimney cap.

Check and change furnace filters every 15 days. Dirty furnace filters will cause furnace overheating and unsafe furnace operating conditions. Handling wood creates dust, thus wood-burning furnaces require more filter changes per season than conventional oil or gas furnaces.

Remove ashes as often as necessary.

Disconnect the furnace power source, and then clean and inspect the blower assembly. Lubricate if necessary.


Side Note 2

Simple Tips for a Warmer Home

Adjust your Fan

It may seem counter intuitive to turn on your ceiling fan during the winter, but most ceiling fans have a switch that controls two settings. The counterclockwise setting cools the room during summer. However, since heat rises, during winter the fan’s clockwise setting forces warm air downward into the living space.

Add Moisture

Anyone who’s spent a steamy summer in Alabama will attest that humid air feels warmer than dry air. For a more comfortable sleep and to soothe sinuses irritated by cold, dry weather, use a humidifier. Both cool mist and warm mist humidifiers are available, but either can make a room feel warmer.

Solar Power

The radiant heat of the sun can be harnessed to heat your home by strategically adjusting your blinds and curtains. On sunny days, open curtains that face southward to let the sunlight in. However, close the curtains at night to provide an additional insulating barrier between cold outdoor air and your home.


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