Heat Pump Blowing Cold Air in Phoenix? What's Normal in Winter and When to Call

Most Phoenix homes heat with a heat pump, the same system that cools all summer, running in reverse. And every December, when Valley nights drop into the 40s and occasionally the 30s, the same question pops up: "Why is my heat pump blowing cold air?"

Sometimes it's completely normal. Sometimes it's a problem you'll want fixed before it becomes a bigger one.

What's normal

The air feels lukewarm. Heat pumps deliver air around 85 to 100 degrees. That's warm, but cooler than your skin, so it can feel cool on your hand. The house should still warm up steadily.

Defrost mode on cold mornings. In cold, damp weather, frost builds up on the outdoor unit. The system briefly switches into defrost to melt it. You may see steam, hear a whoosh and feel cooler air for 5 to 15 minutes. Then normal heating resumes.

It runs longer. Heat pumps run longer, gentler cycles than furnaces. Long run times on a cold night aren't a problem by themselves.

What's not normal

• Cold air that continues for more than 15 to 20 minutes
• Heavy ice on the outdoor unit that doesn't clear
• The outdoor unit isn't running at all
• A big jump in your APS or SRP bill (backup "aux heat" may be running constantly)
• Grinding, rattling or loud buzzing
• The house never reaches the temperature you set

These can point to low refrigerant, a failing reversing valve, a defrost control problem or electrical issues, all of which are worth fixing early.

Quick checks before you call

1. Make sure the thermostat is set to Heat, not Cool or Auto.
2. Make sure it's not stuck on Emergency Heat, which is expensive to run.
3. Replace the filter if it's dirty.
4. Check the breaker for the outdoor unit.
5. Clear leaves and debris from around the outdoor unit.

Still blowing cold? Time for a technician.

Why Phoenix systems need extra attention

Your heat pump cools for most of the year and heats for the rest. That's close to year-round operation, more wear than systems in most of the country ever see. Small problems that hide during cooling season often show up on the first cold night.

The easy fix: the Comfort Club

The Empower Comfort Club puts your system on the schedule for a spring and a fall tune-up every year, so problems get caught before the season changes.

• Standard Maintenance Plan ($19.99/mo): 2 annual tune-ups with our 50-point inspection, a 2-year extended parts warranty and priority service scheduling.
• Advanced Maintenance Plan ($39.99/mo): everything in Standard, plus a 5-year extended parts warranty, a new MERV 13 filter at every visit, one free service call and 15% off parts and service.

If your heat pump acts up on a cold night, Comfort Club members get priority scheduling.

FAQ

Why does my heat pump blow cold air for a few minutes? It's usually defrost mode, which melts frost on the outdoor unit. Normal heating returns within about 15 minutes.

Should I use emergency heat? Only if the heat pump has actually failed. Emergency heat costs a lot more to run.

How often should a Phoenix heat pump be serviced? Twice a year: once before summer and once before winter.

Get your heat back

Schedule a heating repair or tune-up with Empower in the Phoenix metro, or join the Comfort Club and stop worrying about it. Call (602) 581-7022 or visit empoweryourhome.com.