Learn why your heat pump stops delivering warm air, how to diagnose common issues, and when to call a professional for repair.
Heat Pump Not Blowing Warm Air – What’s Going Wrong?
When dealing with heat pump not blowing warm air, the situation where a heat pump runs but fails to deliver hot air into your home. Also known as cold‑output heat pump, it usually points to a specific set of faults inside the system.
The most common trigger is a thermostat, the control device that tells the heat pump when to heat or cool. If the thermostat is miscalibrated or its sensor is stuck, the pump thinks the current temperature is already satisfactory and shuts off the heating cycle. Another frequent culprit is a refrigerant leak, the fluid that carries heat between the indoor and outdoor coils. Low refrigerant pressure means the heat‑exchange process stalls, so warm air never reaches the vents. A failing compressor, the heart of the heat pump that pressurises the refrigerant also stops the cycle entirely, leaving you with cold drafts. In short, heat pump not blowing warm air encompasses thermostat errors, refrigerant loss, and compressor breakdowns, each demanding a different diagnostic step.
Beyond the Basics – Outdoor Unit and Ductwork Checks
The outdoor unit, the external box that houses the compressor, fan and coil can collect debris or suffer ice buildup, choking airflow and preventing heat transfer. Clear any leaves, snow, or dirt and verify the fan spins freely. Equally important is the ductwork, the network of channels delivering conditioned air throughout the house. Leaky or blocked ducts reduce the amount of warm air that reaches rooms, making it seem like the heat pump isn’t working. A quick visual inspection for disconnected sections or obvious gaps can save you a service call. Together, these components form the full pathway from the compressor’s pressure swing to the warm air you feel, so any snag along the line can cause the symptom of no warm air.
Understanding how each piece – thermostat, refrigerant, compressor, outdoor unit, and ductwork – interacts gives you a solid foundation for troubleshooting. Below you’ll find a curated set of articles that dive deeper into each fault, offer step‑by‑step checks, and explain when it’s time to call in a qualified technician.