Preventive HVAC maintenance: what a tune-up should include and why it pays off

Heating and cooling equipment works hardest exactly when you need it most. A breakdown on the hottest day of the year usually started as a small problem weeks earlier: a weak capacitor, a dirty coil, a clogged drain. Preventive maintenance is how you catch those while they’re cheap.

The benefits

• Lower energy bills: clean coils, correct airflow and a correct refrigerant charge let the system do the same work with less electricity or gas.
• Fewer emergency breakdowns: worn parts get replaced on your schedule, not at 9 p.m. in July.
• Longer equipment life: less strain on the compressor and blower motor, the two most expensive parts.
• Safety: a heating check looks for gas leaks, venting problems and cracks in the furnace heat exchanger, which can let carbon monoxide into the home.
• Warranty protection: many manufacturer warranties can require proof of regular professional maintenance. Check yours and keep your receipts.

When to schedule

ENERGY STAR recommends a pre-season checkup: the cooling system in spring and the heating system in fall. Contractors are busiest once the weather turns, so booking early is easier and often cheaper. In hot climates like Las Vegas, many homeowners do their AC check in March or April, before the first 100-degree days.

What a cooling tune-up should include

• Check thermostat settings and operation.
• Inspect and tighten electrical connections, and measure voltage and current on the motors.
• Test capacitors and contactors, which wear out fastest in extreme heat.
• Clean the outdoor condenser coil and check the indoor evaporator coil.
• Check the refrigerant charge and look for signs of leaks.
• Clear and test the condensate drain line so it can’t back up and cause water damage.
• Inspect the blower and lubricate moving parts where the manufacturer calls for it.
• Check airflow and the filter, and watch a full start-up and shut-down cycle.

What a heating tune-up adds

• Check gas connections, gas pressure, burner operation and flame.
• Inspect the heat exchanger and flue for cracks, corrosion or blockages.
• Test safety controls such as the limit switch and flame sensor.
• For heat pumps, check the defrost cycle and backup heat.

What you can do yourself

• Check the filter monthly and replace it when it’s dirty.
• Keep at least 2 feet of clearance around the outdoor unit: trim plants and move debris, trash cans and stored items.
• With the power off at the outdoor disconnect, gently rinse dust off the outdoor coil from the inside out with a garden hose. Never use a pressure washer.
• Keep supply vents and return grilles open and unblocked by furniture or rugs.

Maintenance plans

Many contractors offer yearly plans that bundle spring and fall visits, often with priority scheduling and repair discounts. They can be good value if you’d schedule the visits anyway. Read what’s included, and whether parts like capacitors are covered or extra.