Heat Pump Not Blowing Warm Air? Here’s What’s Really Going On

When your heat pump, a device that moves heat from outside to inside your home to provide warmth. Also known as air source heat pump, it should deliver steady heat even in cold weather—but when it stops blowing warm air, something’s wrong. This isn’t just about comfort. It’s often a sign of a failing part, poor maintenance, or a system pushed beyond its limits.

A heat pump compressor, the heart of the system that circulates refrigerant to transfer heat is the most expensive component to replace—and if it’s failing, your heat pump won’t generate enough warmth. But before you panic about a $3,000 repair, check the basics. A dirty air filter, blocked outdoor unit, or faulty heat pump thermostat, the control that tells the heat pump when to turn on and off can cause the same symptom. Many homeowners think their heat pump is broken when it’s just stuck in cooling mode or has a tripped reset switch. Even low refrigerant levels, often caused by small leaks, can make the system blow cool air instead of warm.

And don’t ignore the heat pump maintenance, regular cleaning and inspection that keeps the system running efficiently. If you haven’t cleaned the coils, checked the drain line, or replaced the filter in over a year, dirt and debris are likely choking airflow. A heat pump needs clear space around it, especially outside. Snow, leaves, or even tall grass can block the unit’s ability to pull in heat from the air. And if your system is over 10 years old, parts like capacitors or fan motors wear out—and those are cheaper fixes than a compressor.

Some people assume that if their heat pump isn’t warm enough, they need a new one. But that’s not always true. A 7-year-old heat pump with a bad fan motor or a clogged air filter can be fixed for under $300. A 15-year-old unit with a failing compressor? That’s where replacement makes more sense. The key is knowing what’s broken before you spend money. That’s why so many homeowners end up calling a technician only to find out the problem was simple—and fixable.

Below, you’ll find real fixes from people who’ve been there. From how to test your thermostat to spotting early signs of compressor trouble, these posts cut through the noise. No fluff. Just what actually works when your heat pump stops heating.