The short answer
The heat pump mistakes that cost Northern Virginia homeowners the most all come from treating it like a gas furnace: flipping on emergency heat when it gets cold, dropping the thermostat overnight, and panicking at frost and steam that are completely normal. Leave it on Heat, pick a temperature and keep the outdoor unit clear. Here’s the rest of the list, and the few things that really are a problem.
What we’d stop today
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| Don’t | Why | Do this instead |
|---|---|---|
| Switch to Em Heat because it’s cold | It shuts off the heat pump and runs the whole house on electric strips, the most expensive heat there is. | Leave it on Heat. Backup comes on by itself when it’s needed. |
| Turn it way down at night | Coming back up brings on the strips, and they can cost more than you saved. | Pick a temperature and leave it. |
| Bump it up five degrees to warm up faster | A big jump can call for the strips too, and the house doesn’t heat any faster for it. | Go up a degree or two at a time. |
| Put a tarp or cover on it | It needs air moving through the coil all winter. | Leave it open. |
| Chip ice off with a screwdriver | The fins bend like foil, and a poke in the coil means a refrigerant leak. | Let defrost work. If it can’t, turn it off and call. |
| Let snow pile up around it | Snow blocks the air, and the melt needs somewhere to go. | Clear a couple of feet around it after a storm, gently. |
| Let a gutter drip on it | That water freezes on top of the unit and keeps building. | Fix the gutter over it. |
| Forget the filter | It’s the same filter and the same blower as any other system, and a clogged one hurts a heat pump year round. | Pull it and look every month or so. |
The $67 Heating Check
We check your furnace, heat pump or boiler before winter. Through December 31. See the offer
The thermostat, because that’s where the money goes
Emergency heat exists for one situation: the heat pump is broken and you need heat until somebody can get there. Leave it on after a cold snap and you’ll meet it again on the electric bill. If your bill jumped and nobody knows why, start with what a doubled heating bill usually means. And aux heat and emergency heat aren’t the same thing. Aux comes on by itself and is usually fine. Em Heat is a switch somebody flipped.
The Department of Energy makes the same point about setbacks in its heat pump guidance: avoid the ones that force the backup heat to run. Our best thermostat setting post has the numbers for gas and heat pump houses side by side.
What looks wrong and isn’t
- Frost on the coil. The outdoor coil runs colder than the air, so moisture freezes on it.
- Steam off the unit. That’s defrost melting that frost.
- A whoosh, then the fan stops for a few minutes. Also defrost. The system reversed itself and will switch back.
- Water around the base. That’s where the melt goes. Keep it from turning into a skating rink on your walkway.
- Air at the vent that feels cool on your hand. It’s warmer than the room, just not as hot as what a gas furnace puts out. Here is why a heat pump still works in a Virginia winter.
What really is a problem
- The coil is locked in solid ice, or ice is building over the top of the cabinet. Turn it off at the thermostat, switch to Em Heat to stay warm and call. That’s what the switch is for.
- Heavy ice comes back within an hour of clearing. That points to a defrost failure or a refrigerant problem, and running it that way can damage the unit.
- Aux heat runs all the time in mild weather. Cold air from the vents or a high bill usually shows up alongside it.
- The outdoor unit isn’t running while the house is calling for heat, or it is blowing cold air outside and you can’t tell if that’s right. It’s a quick question for a tech.
- Grinding or screeching from outside. Turn it off before a bad bearing becomes a bad motor.
If the power goes out
Don’t bring a generator or a grill indoors, and don’t run a space heater off an extension cord. Our winter power outage post has the whole plan for heat and pipes, and the space heater list has what not to do with one. When the power’s back, turn things on one at a time.
If it’s getting old
Don’t let January pick the date. If yours is near the end, look at what heat pump repairs run and whether dual fuel makes sense for your house while there’s still time to think about it.
Questions people ask
Should I turn my heat pump to emergency heat when it’s really cold?
No. Cold weather alone isn’t a reason. The system brings on its backup heat by itself when it needs to. Save the Em Heat setting for when the heat pump is broken and you’re waiting on a technician.
Is ice on my heat pump normal in winter?
A light coat of frost that clears on a cycle is normal. A coil locked in solid ice, or heavy ice that comes back within an hour of clearing, isn’t. Turn it off and call.
Why is there steam coming off my heat pump?
That’s the defrost cycle melting the frost off the coil. It runs for a few minutes, and you may hear a whoosh when it starts and stops.
Should I cover my heat pump in winter?
No. A heat pump runs all winter and needs to pull air through the coil. A cover is for an AC that’s shut down for the season, and even then only a top panel.
Book it
Want somebody to look it over before the real cold shows up? Book a check now, because the schedule fills on the first hard freeze. The heating check is $67 per system through December 31, on a furnace, heat pump or boiler. Book it from goswiftpro.com/cookiesoffer and free MOLTN cookies come with the visit. Or call (703) 997-9757. SwiftPro is rated 5.0 stars across 1,138 reviews on Google, Angi, Yelp, the BBB and Facebook, Virginia Class A license 2705192276.
