Dealing with a freezing heat pump can be alarming, especially when the temperatures drop. If you notice your outdoor unit coated in ice, your first thought might be that your system is broken.
The good news is that a small amount of frost is normal. The bad news is that a heavy layer of ice can prevent your heat pump from doing its job—keeping your home warm.
Before you panic and call for an emergency service, here’s a guide from Poormans on what to do if your heat pump freezes in the winter.
Heat pumps operate by extracting heat from the outdoor air, even when it’s cold outside. This process naturally causes the outdoor coil to get very cold, which leads to the creation of frost or a light layer of ice.
The Defrost Cycle: Normal
Modern heat pumps are designed to handle this through an automatic Defrost Cycle.
- When the unit senses the coil is too frosty, it temporarily switches to a cooling cycle, essentially warming the outdoor coil to melt the ice.
- The fan usually shuts off during this time to speed up the process.
- This cycle typically lasts between 5 to 15 minutes.
- You may see steam rising from the unit—this is completely normal!
Excessive Ice: Abnormal
If the heat pump is heavily encased in ice and remains frozen for more than an hour, or if the ice is thick enough to cover the fins or the base of the unit, then you have a problem.
4 Steps to Take When Your Heat Pump Is Frozen Solid
If you suspect your defrost cycle has failed, or if the ice buildup is excessive, follow these steps immediately:
Step 1: Check Your Thermostat
First, ensure your thermostat is set correctly. Check that:
- It is set to “HEAT” (not “COOL”).
- The fan is set to “AUTO.”
- The temperature setting is high enough to trigger the heat.
Step 2: Switch to Emergency Heat (If Available)
If your heat pump cannot efficiently pull heat from the air due to the ice, it’s best to switch the system over to Emergency Heat or Auxiliary Heat.
This will turn off the outdoor unit and switch your home over to a secondary heating source (usually electric resistance coils in your air handler). This process uses more energy, but it will keep your home warm and prevent further damage to the heat pump while it thaws.
Step 3: Manually Clear the Area (Safely!)
Never attempt to chip away the ice with a hammer, shovel, or sharp object—you could easily damage the delicate metal fins or coils, leading to very costly repairs.
Instead, you can:
- Turn Off the Power: Locate the dedicated power disconnect switch (usually on the wall near the outdoor unit) and flip it off.
- Use Warm Water: Gently pour lukewarm water over the coils and base of the unit to help melt the ice. Do not use boiling water, as the sudden temperature change can crack components.
- Wait for a Natural Thaw: If the weather is expected to warm up slightly, you can simply leave the unit powered off on Emergency Heat and allow it to thaw naturally.
Step 4: Call Your Local HVAC Experts
Once the ice has melted, switch the power back on and return the thermostat to its regular “HEAT” setting. If the unit freezes again quickly, there is an underlying mechanical issue that needs professional attention. If your old heat pump may be due for replacement, contact a local Trane dealer like Poormans, or browse the replacement options on the Trane website.
Common Reasons for Freezing
A recurring freeze-up is usually caused by one of these mechanical problems:
- Faulty Defrost Control Board or Sensor: The system isn’t initiating the defrost cycle when it should.
- Low Refrigerant Levels: Low refrigerant causes a drop in pressure, making the coils excessively cold and prone to icing. This requires immediate professional repair.
- Blocked Airflow: Debris, leaves, or mulch surrounding the unit can restrict airflow and encourage icing.
- Clogged Drain Pan: If the condensate drain pan is clogged, the water can’t drain and refreezes around the base.
Air conditioner owners can have these issues too, click here to check out our blog on how to keep your AC safe in the winter.
Don’t Wait for a Deep Freeze!
If your heat pump is freezing, especially multiple times in a season, it’s a clear sign that a key component is failing. Running a frozen system puts incredible strain on the compressor and can lead to total system failure.
If you are dealing with a frozen heat pump in the Fort Wayne area, don’t risk further damage.
Contact the experts at Poormans today at 260-422-3534 to schedule an inspection and thaw your system safely!