Why Is My Heat Pump Not Cooling on Hot Days?

A heat pump usually won’t cool on hot days because airflow is restricted, coils are dirty, refrigerant is low, the thermostat is mis-set, or a key component has failed. The most common cause is a clogged air filter or a blocked outdoor unit that starves the system of air. On the hottest afternoons, a heat pump may run nonstop, but it should still bring the temperature down steadily. We fix these problems for homeowners near Cropsey and across the Bloomington–Normal area. Summers Plumbing Heating & Cooling provides 24/7 emergency heat pump repair and routine tune-ups, and twice‑a‑year maintenance helps protect manufacturer warranties and prevent surprise breakdowns.

Check these quick items before calling:

• Replace a dirty filter and set the thermostat to Cool with the fan on Auto.
• Clear leaves and grass from around the outdoor unit and gently rinse the coil fins.
• If airflow is weak, the outdoor fan stops, ice forms, or breakers trip, stop use and schedule service.

If the outdoor unit or refrigerant lines are iced, turn the system off and let it thaw before a technician inspects it. <br/> Updated: 2026-04-04 <br/> Need help in Cropsey, IL? Call (309) 317-4215 or book online. "The service was professional, thorough, and completely hassle-free." — Steve W.