HVAC questions, answered
How often should my furnace or air conditioner be serviced?
Once a year for each system is a sensible routine: heating before winter and cooling before summer. Heat pumps do both jobs, so a spring and fall check is common. Replace or clean the filter far more often, usually every one to three months depending on the filter type, pets and dust.
Why is my air conditioner blowing warm air?
The most common causes are a tripped breaker or blown fuse at the outdoor unit, a failed capacitor or contactor, a dirty filter or coil, or low refrigerant from a leak. Check the thermostat setting and the breaker first. If the outdoor unit hums without the fan turning, switch the system off and call for service to protect the compressor.
Is it normal for a heat pump to run constantly in cold weather?
Long run times are normal for a heat pump on very cold days, because it heats steadily rather than in short bursts. It is not normal for the house to keep losing ground, for the outdoor unit to stay coated in ice, or for the system to blow cold air for long periods. Those point to a defrost, refrigerant or sizing problem.
How do I know what size system my house needs?
The right size comes from a load calculation that accounts for insulation, windows, air leakage, orientation and your local climate. Square footage rules of thumb and matching the old unit's size are both unreliable. Ask any contractor quoting a replacement to show you how they sized the system.
What do SEER2 and EER2 mean?
SEER2 measures cooling efficiency over a typical season, and EER2 measures efficiency at a single hot-weather condition. Both were introduced with the federal test procedure that took effect in 2023, so they are not directly comparable to older SEER and EER numbers. Higher is more efficient. The minimum you can install depends on your region.
What should I do if I smell gas near my furnace?
Leave the house right away without switching lights or appliances on or off, and call your gas utility or 911 from outside. Do not return until the utility says it is safe. Once the gas issue is resolved, have the furnace inspected before it is used again.
Should I repair or replace my old furnace?
Compare the repair cost with the system's remaining life and running cost. A modest repair on a sound, correctly sized furnace is usually worth it. A major repair such as a heat exchanger on an older, inefficient furnace is often the point where replacement makes more sense. Ask for both prices in writing.
Do I need a permit to replace my HVAC system?
In most cities and counties, yes. Replacing a furnace, air conditioner or heat pump usually needs a mechanical permit and an inspection. Ask your contractor who pulls the permit and whether its cost is included in the quote.
Why are some rooms always hotter or colder than others?
Uneven temperatures usually come from duct problems such as leaks, crushed runs or undersized returns, from blocked registers, or from rooms with more sun or less insulation. A contractor can measure airflow at each register to find the cause. Zoning or a ductless unit can help rooms that can't be balanced any other way.
How long does a new HVAC installation take?
A straightforward replacement of similar equipment often takes a day or two. Switching system types, changing ductwork, adding electrical capacity or waiting on permits can add time. Ask for the schedule in writing, including when the permit inspection is expected.
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