When your heat pump, a device that moves heat from one place to another to warm or cool your home. Also known as air source heat pump, it works like a reversible air conditioner—pulling heat from the air outside to warm your house in winter, and reversing that process to cool it in summer. stops cooling, it’s not just uncomfortable—it’s costing you money. Many people assume a heat pump that won’t cool means it’s broken beyond repair, but often it’s just a clogged filter, low refrigerant, or a dirty outdoor coil. These aren’t always expensive fixes, and sometimes you can spot them yourself.
One of the most common reasons a heat pump won’t cool is a dirty air filter. If you haven’t changed it in months, airflow gets restricted. That makes the system work harder, and eventually, it can’t pull enough heat out of your indoor air. Another big one is refrigerant leaks. Unlike your car’s coolant, refrigerant doesn’t get used up—it should last the life of the unit. If levels are low, something’s leaking. That’s not a DIY fix, but catching it early saves you from a full system replacement. Then there’s the outdoor unit. Leaves, dirt, and grass clippings pile up around it, especially after storms. If the coils are covered, the heat pump can’t release heat outside, so it can’t cool inside. A quick hose-down (with the power off!) can make a big difference.
Thermostat issues are another sneaky culprit. If it’s not sending the right signal, your heat pump might stay in heating mode even when you want cooling. Try switching it to cooling, setting the temperature lower than the room, and waiting a few minutes. If nothing happens, check the batteries or reset it. And don’t ignore strange noises—hissing, grinding, or clicking can point to a failing compressor or fan motor. These are signs you need a pro, but knowing what to listen for helps you avoid being overcharged.
Heat pumps are designed to last 10 to 15 years. If yours is older than that and suddenly stops cooling, it’s worth checking if replacement parts are even available. Some models from 10+ years ago use discontinued components, making repairs more expensive than a new unit. But if your heat pump is under 10 years old, chances are it just needs a tune-up. Regular maintenance—cleaning coils, checking filters, inspecting ducts—can double its life. A lot of the posts below walk you through exactly how to spot these issues before they turn into full breakdowns.
Below, you’ll find real-world guides from people who’ve been there—how to test your heat pump, what tools you need for basic checks, and when to call a technician instead of wasting time. No fluff. Just what actually works.
8 November 2025 · 0 Comments
Your heat pump runs but doesn't cool? It's usually a simple fix like a dirty filter or thermostat setting. Learn the top 5 causes and how to fix them yourself before calling a technician.
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