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- Normal or not?
Normal or not? Sights, sounds and smells
Heat pumps and air conditioners make noises, drip and sometimes steam. Most of it is part of how they work. Here's how to tell what's fine from what needs a call.
What you're seeing or hearing
General guidance for heat pumps, air conditioners and furnaces. If in doubt, switch the system off and call us.
- Normal
Heating
Steam rising from the outdoor unit
A defrost cycle on a cold morning. The unit melts the frost off its coil, and the melt turns to steam. It stops within a few minutes.
- Normal
Heating
Outdoor fan stops, then a whoosh
Also defrost. The valve switching over makes a whoosh; the fan restarts when it's done.
- Normal
Heating
Warm air, not hot
A heat pump delivers warm air for longer, rather than short blasts of hot air like a gas furnace. It still heats the room.
- Normal
Heating
Dusty smell on the first cold day
Dust burning off the heater after months unused. It should fade within an hour or so.
- Normal
Cooling
Water dripping from a pipe outside
Condensate — moisture pulled out of your indoor air. A steady drip from the drain line on a warm day is what it should do.
- Normal
Cooling
Warm air blowing out of the outdoor unit
That's the heat taken out of your home being released outside.
- Normal
Any season
A click, then the fan starting
Relays and the thermostat switching on. A single click at start and stop is expected.
- Call
Cooling
Ice on the indoor unit or copper lines
Usually low airflow or low refrigerant. Switch cooling off, leave the fan on to thaw, and call us.
- Call
Heating
Outdoor unit covered in ice for hours
Light frost is normal. A block of ice that never clears means defrost isn't working.
- Call
Any season
Water pooling indoors
Around the furnace, air handler or under a wall unit. Usually a blocked or broken drain — turn the system off to limit damage.
- Call
Any season
Grinding, screeching or banging
Moving parts rubbing or loose. Switch off before a small repair becomes a motor or compressor.
- Call
Any season
Burning plastic or electrical smell
Unlike the first-day dust smell, this doesn't fade. Turn the system off at the thermostat and the breaker.
- Call
Any season
Starts and stops every few minutes
Short cycling wears equipment out fast. Often a thermostat, sensor, airflow or sizing problem.
- Call
Any season
The breaker keeps tripping
Don't keep resetting it. Leave it off and call us.
Smell gas? Leave first.
A rotten-egg smell near a furnace, water heater or stove is not a service call. Get everyone outside, don't switch anything on or off, and call the gas company or 911 from outside. We can repair the appliance once it has been made safe.
