When your heating system needs attention
Most heating failures give some warning first. Catching them early usually means a smaller repair and avoids a no-heat call on the coldest night of the year. Heating systems in this region range from gas furnaces to air-source heat pumps to the occasional boiler, but the early signs of trouble are similar.
Common signs of a heating problem
- Short cycling. The system starts, runs for a minute or two, shuts off and starts again. Causes range from a clogged filter or a dirty flame sensor to an oversized furnace or a failing limit switch.
- Uneven rooms. One end of the house stays cold while the other is comfortable. That can point to duct leaks, closed or blocked registers, or a blower that isn't moving enough air.
- New noises. Banging at ignition, squealing from the blower, or grinding from a motor bearing all deserve a look before they turn into a breakdown.
- Yellow or flickering burner flames on a gas furnace, soot around the burners, or a smell of gas. If you smell gas, leave the house and call your gas utility from outside before you call anyone else.
- Rising bills without a change in habits. Gradual efficiency loss is easy to miss month to month but obvious when you compare one winter with the last.
- A heat pump that runs constantly or blows lukewarm air in cold weather. Some of this is normal in deep cold, but a system that never catches up may be low on refrigerant or stuck in the wrong mode.
Repair or replace?
There is no single age at which a furnace or heat pump must be replaced. A useful way to decide is to weigh the repair cost against the system's remaining life and its running cost. A modest repair on a sound, correctly sized system is usually worth doing. A major repair, such as a heat exchanger or compressor, on an older system that already runs poorly is often a good moment to price a replacement instead.
A cracked heat exchanger on a gas furnace is a safety issue, not just a repair. If a technician reports one, ask to see the evidence, ask how they tested for it, and get a second opinion if you are unsure.
If you are considering switching from gas heat to a heat pump, ask the contractor to size the new system with a load calculation rather than matching the old furnace's rating, and ask how the heat pump will perform at your area's winter design temperature. Your city page lists local design temperatures and any utility rebates we could confirm.
What a heating service visit should include
A thorough tune-up or repair visit typically includes:
1. Replacing or checking the air filter and confirming the correct size and type. 2. Testing ignition, flame sensing and safety limits on a furnace, or defrost operation and refrigerant pressures on a heat pump. 3. Checking the blower motor, wheel and electrical connections. 4. Testing for carbon monoxide at the furnace and in the living space on gas systems. 5. Measuring temperature rise or temperature split to confirm the system is moving heat the way it should. 6. A written summary of what was found, what was fixed, and anything recommended for later, with prices.
Questions to ask the contractor
- What exactly failed, and how did you confirm it?
- Is the part under any manufacturer warranty?
- If you recommend replacement, will you do a load calculation, and will a permit and inspection be part of the job?
- What is included in the price, and what could change it once work starts?
- How do you handle a problem that comes back after the repair?
A good contractor will answer these plainly and put the answers in writing.