Heat pumps, as efficient as they can be, sometimes get stuck in different settings. For example, poor heat pump maintenance can cause the unit to overheat and fail to turn on. So, what kinds of problems can keep a heat pump stuck in defrost mode?
Cooper’s Plumbing & Air experts provide 24/7 heat pump repairs in Tallahassee, TN. We’ve often seen the following four issues make a heat pump malfunction and flounder in its defrost cycle. Don’t worry; we’ll tell you how to fix them.
Clogged or Dirty Outdoor Unit
Defrosting heat pumps gather heat from inside the house and send it to the coils outside to melt any outdoor unit frost buildup. Even so, it can’t suddenly melt off mud, leaves, or other caked-on muck. If you haven’t cleaned up your yard, you likely haven’t checked on your outdoor unit, either.
A dirty unit has poor airflow, and poor circulation contributes to frost buildup. Moreover, dust can create more surface space for ice to grow on. That’ll keep your heat pump stuck in defrost mode for sure.
Cleanup Time
You can use a water hose in above-freezing weather to wash the unit’s fins. Avoid using water in freezing temperatures; otherwise, you’ll only contribute to the ice.
In either case, have a broom or rake and a soft brush on hand. Use the soft brush to clean the outdoor unit’s fins carefully; you don’t need to exert much force. You can then use the broom or rake to clean up around the unit, removing dust and leaves from the premises.
Temperature Sensor or Control Board Issues
Heat pumps and many other temperature control units rely on sensors to determine when to use your electricity. The sensors connect to a thermostat or defrost control board to function.
For instance, a room drops below a desired temperature, and the sensor detects the drop. It sends a signal to the thermostat, which turns on the unit. The unit, a heat pump in this case, runs until the room reaches the desired temperature, then all systems rest.
HVAC systems with problematic sensors or glitchy control boards cannot function properly. If you find your heat pump stuck in defrost mode in winter, the thermostat could be indicating you want cooling instead of heating.
Check and Repair Where Needed
Some sensors use batteries while others don’t; it depends on the system you have. If you know where your temperature sensors are, you can check them to see if they’re bent or out of battery.
Those that don’t use batteries may be out of shape and unable to function. You can usually find replacements for them at hardware stores that carry HVAC supplies.
Your control board should have come with instructions for restarting it, which can usually resolve most glitches. You may also find the instructions on the manufacturer’s website, or you could request them by contacting them.
However, if you find that these issues take too much time to deal with, our team is always ready to help.
Low Refrigerant Levels
Both heat pumps and air conditioners rely on refrigerant, but the reversing valve allows heat pumps to provide both heating and cooling. We just happen to also call a heat pump’s cooling mechanism its defrost mode since the science behind its heating interests us most.
Think of refrigerant like the lifeblood of the heat pump. Without it, it cannot exchange heat energy with its environment. It completely loses its purpose.
What does this have to do with a heat pump stuck in defrost mode, though?
Sometimes a heat pump will cycle in defrost mode if there’s too little refrigerant in its coils. This often means there’s a refrigerant leak, which can be very dangerous for your health and the environment. Sound the alarm if you notice these refrigerant leak signs:
- No freezing weather, but ice on your evaporator coils
- Hissing or bubbling sounds coming from your system
- A sweet sort of smell, like nail polish remover, near a coil or valve
- Oil spots on joints, tubes, or near HVAC components
Do Not Try To DIY
Hire an HVAC specialist to diagnose your system and refill your refrigerant. This toxic substance, while very useful, can cause serious harm because it is under immense pressure in its container.
If you make a mistake with refrigerant, it can get into your lungs, causing acute refrigerant poisoning. It can also spread into the local ecosystem, leading to further issues and potential legal fines. Leave refrigerant refills, as well as line repairs and replacements, to qualified, trained contractors.
Poor Installation or Sizing
People can make mistakes when constructing or refurbishing a house. When installing a heat pump, they may use one that is too large or too small for the property.
Too small, and the heat pump will never turn off, unable to properly heat the house. Too large, and the heat pump will likely short-cycle, constantly turning on and off in quick succession. Both situations make the heat pump prone to icing over, malfunctioning, and using excessive amounts of energy.
Try Something New
While you might be able to adjust the vents or unit placement to correct a poor installation, bad sizing is a different story. This can only be fixed with a new unit. While it may be expensive up front, it often beats paying exorbitant electric bills.
You will need a trustworthy, qualified HVAC contractor to properly evaluate your home, its size, and your needs. Once we collect that information, we can help you choose and install a new, much more suitable heat pump.
Your Long-Term Heat Pump Solution in Tennessee
The team at Cooper’s Plumbing & Air excels at hands-on communication, thorough repairs, and long-lasting HVAC replacements. When we install, maintain, or repair a unit, we keep it working as long as possible.
If you find your heat pump stuck in defrost mode in the middle of the night, no worries. We’re available 24/7 with no extra “after-hours” charges for services.
Are you looking for a free estimate on various heat pump systems and repairs? Visit our contact page or call 866-464-7132 today!