Is your heat pump running constantly—and you’re wondering if it’s about to wave a white flag? It’s hot and humid outside, but you want to spot any potential issues before they turn into costly repairs. It’s true that extended running can be completely normal, so how do you know when your equipment is struggling and in need of heat pump repairs? Continue reading to learn how to know the difference between normal and problematic, get practical advice on what you can check, and find out when to call in the pros.
Common Reasons for Heat Pumps Running Nonstop
Variable-speed or inverter model heat pumps thrive when allowed to modulate at low levels. By running continuously at a lower capacity, they reduce humidity, avoid short cycling, and maintain a more even temperature. Simply put, modern heat pumps are designed to run for longer periods at lower speeds. This approach maintains steady temperatures, improves dehumidification, and reduces energy spikes caused by frequent starts and stops. Some common reasons your heat pump may run longer include:
- Outdoor temperatures are in the high 80s or 90s: As the outdoor temperature climbs, your heat pump operates longer to remove heat from inside your home and maintain the set indoor temperature. During prolonged heat waves, it’s perfectly normal for your unit to run most of the day to keep up.
- Your thermostat is set to 70°F or lower: While not always a problem, setting your thermostat too low during extreme heat can make your system run longer, or even nonstop. When the system runs continuously to try to reach the desired temperature, it can cause the indoor evaporator coil to become too cold and freeze.
- Your home gets direct sun or has poor insulation: Solar heat gain and poor thermal protection inside your home can lead to longer cooling cycles. Homes without adequate attic insulation or UV window films may feel hotter and take longer to cool down, making your heat pump run longer than average.
When Constant Operation Might Be a Red Flag
If your heat pump is running all day and your home still doesn’t feel cool, it may be trying to overcome a problem. Here are a few potential culprits:
- Dirty Air Filter: A clogged filter restricts airflow and efficiency. When airflow is blocked, your heat pump can’t move cooled air through your home properly, leading to longer runtimes as it works to catch up.
- Blocked Outdoor Unit: Grass clippings, weeds, or leaves crowding your outdoor unit can reduce its ability to release heat. That makes the system less efficient, especially in high heat, and forces it to run longer to keep up with demand.
- Low Refrigerant: Refrigerant is what allows your heat pump to absorb and move heat. A leak or undercharge limits this ability, meaning your system may run constantly with little cooling impact. Refrigerant issues require a professional to diagnose and repair.
- Duct Leaks: Holes or poorly sealed ducts can leak cooled air into crawl spaces or attics, making it harder to cool your home. Your system might run constantly just to compensate for that loss.
- Improper Sizing or Installation: If your heat pump is too small for your square footage, or if it was installed incorrectly, it may never be able to cool your home effectively. In these cases, no amount of runtime will achieve the set temperature.
- Thermostat Issues: A miswired or malfunctioning thermostat might not be sending proper signals to cycle the system on and off. If your unit seems to ignore the temperature setting, it could be an issue with the control system rather than the equipment itself.
DIY Tips You Can Try
Before you call a technician, try these homeowner-friendly fixes:
- Replace your air filter if it’s dirty or older than a month. A clean filter improves airflow and helps your system operate efficiently.
- Clear debris around the outdoor unit and gently spray off the coils. Just a few inches of space around your outdoor unit can dramatically improve heat dissipation and reduce runtime.
- Close blinds or curtains during peak sun hours. Reducing solar heat gain lowers the cooling load on your system.
- Set your thermostat to 74–78°F for optimal performance. This range balances comfort and efficiency, especially during extreme heat.
- Make sure all vents are open and unobstructed. Closed or blocked vents disrupt airflow and force your system to work harder.
Get Home Comfort Help with Local Heat Pump Experts
While long run times are somewhat to be expected during a hot, humid summer, if your utility bill spikes and your home comfort stays the same (or gets worse), you may need to call the pros.
Precision Comfort Systems’ expert HVAC technicians understand how Central Indiana summer affects your home comfort, and we are experienced with heat pump repair and replacement. Whether you need a quick tune-up or a more thorough system check, call (317) 867.2665, or schedule service online.