What to do before an ice storm hits your heat pump
The best protection for your heat pump during an ice storm is preparation before the weather arrives. Clear leaves, dirt, and debris from around the outdoor unit so ice and snow can fall away freely instead of piling up against the fins. Trim back tree branches that hang over the unit—ice-laden branches can snap and damage the coils or fan.
Check that your unit sits on a level, stable pad. If it has settled or tilted, water and ice will pool unevenly and freeze in ways that block airflow. If you notice tilting, contact an HVAC technician to have it releveled before winter storms arrive.
Install a weatherproof cover designed for heat pumps—not a solid tarp that traps moisture. A proper cover has vents that let air circulate while blocking snow and ice from falling directly into the unit. Solid tarps trap condensation and can cause rust and corrosion. Remove the cover as soon as the storm passes so the unit can operate normally.
Key Takeaways
- Clear debris and trim branches around your outdoor unit before ice storms so snow and ice can fall away instead of accumulating against the coils.
- Use a vented weatherproof cover during the storm, not a solid tarp, because solid covers trap moisture and cause rust.
- Do not pour hot water on ice buildup—the sudden temperature change can crack the coils; instead, let ice melt naturally or use a plastic scraper.
- If ice blocks the outdoor unit completely or your heat pump stops heating, turn it off and call an HVAC technician rather than running it in a damaged state.
- Your heat pump can usually switch to backup electric heat automatically if the outdoor unit freezes; check your thermostat settings before the storm.
How to remove ice safely without damaging the coils
If ice builds up on your outdoor unit during the storm, resist the urge to chip it away with a hammer or screwdriver. The aluminum fins inside are thin and bend easily—one wrong strike can puncture a refrigerant line or crack a coil, which requires an expensive repair or replacement.
Never pour hot water on the unit. The sudden temperature change can crack the coils or freeze the water into a thicker layer. Instead, let ice melt naturally as temperatures rise after the storm. If you need to clear ice before the weather improves, use a plastic scraper or a soft brush and work gently from top to bottom, following the direction the fins run.
If ice has completely blocked the intake or outlet vents, you can carefully pour room-temperature water around the edges to help it melt, but do not direct water into the unit itself. The goal is to let gravity and rising temperatures do the work, not to force the ice off.
When your heat pump stops working in freezing weather
Heat pumps are designed to operate in cold weather, but extreme ice storms can overwhelm them. If your unit stops heating or you hear unusual grinding or squealing sounds, turn it off at the thermostat when ready. Running a frozen or damaged unit can cause the compressor to fail, which is the most expensive component to replace.
Most heat pump systems have a backup electric heat setting on the thermostat, usually labeled "Emergency Heat" or "Aux Heat." When you switch to this mode, the system stops trying to use the outdoor unit and heats your home with electric resistance coils instead. This keeps you warm while you wait for an HVAC technician to inspect the outdoor unit for damage.
Check your thermostat now, before a storm arrives, so you know how to switch to backup heat if you need to. The location and label of this setting varies by thermostat model—some have a physical switch, others use a menu screen. If you cannot find it, take a photo of your thermostat and contact your HVAC company to confirm the steps.
Defrost cycles and why your heat pump may cycle on and off
During freezing rain or wet snow, your heat pump's outdoor coils can frost over even while the system is running normally. When this happens, the unit automatically enters a defrost cycle—it reverses direction briefly to warm the outdoor coils and melt the frost, then returns to heating your home.
During defrost, you may notice warm air stops coming from your vents for a few minutes, or you may hear the fan slow down or stop. This is normal and expected. The cycle usually lasts 5 to 15 minutes. If defrost cycles are happening very frequently—more than once every 20 or 30 minutes—the unit may be struggling with heavy ice buildup, and you should contact an HVAC technician.
Some newer heat pumps have sensors that detect frost and run defrost cycles only when needed, which saves energy. Older units may run defrost on a timer regardless of conditions. Either way, the cycle is automatic and you do not need to do anything—just understand that brief heating interruptions during an ice storm are normal operation, not a sign of failure.
Protecting the outdoor unit from snow and ice accumulation
Heavy, wet snow can pile up against the outdoor unit and block airflow, forcing the compressor to work harder and reducing heating output. If snow is falling heavily during the storm, you can gently brush accumulated snow away from the sides and top of the unit using a soft broom or your hand—do not use a shovel or hard tool that could damage the fins.
Never pile snow directly against the unit or use it as a windbreak. Snow blocks the intake vents and traps cold air around the coils, which reduces efficiency and can cause the unit to ice over faster. Keep at least 2 to 3 feet of clear space on all sides of the outdoor unit, even during the storm.
If you have a ground-level unit and snow drifts are expected, you can build a snow fence or barrier 3 to 4 feet away from the unit to redirect drifting snow. Do not build the barrier directly against the unit—the goal is to guide snow around it, not toward it.
What not to do during an ice storm
Do not turn off your heat pump entirely during the storm, even if it seems to be struggling. The system is designed to handle freezing weather, and turning it off means you lose heating and may have to rely entirely on backup electric heat, which is less efficient. Let the heat pump run and cycle normally unless you hear grinding sounds or the unit stops producing heat altogether.
Do not cover the outdoor unit with a solid tarp or plastic sheeting without vents. Moisture will condense underneath and freeze, creating a solid block of ice that is harder to remove than natural snow and ice. It also traps humidity that corrodes the metal components inside.
Do not attempt major repairs yourself. If the unit is damaged, leaking refrigerant, or making unusual noises, call an HVAC technician. Refrigerant lines are pressurized, and opening them without proper equipment is dangerous and illegal in most places.
After the ice storm passes
Once the weather clears, remove any weatherproof cover you installed and inspect the outdoor unit for visible damage. Look for bent fins, cracks in the plastic housing, or ice still clinging to the coils. If the unit looks intact and is producing warm air normally, you can resume regular operation.
If you had to switch to backup electric heat during the storm, switch back to normal heat pump mode on your thermostat. Backup heat uses significantly more electricity and should only run when the heat pump cannot operate.
If the unit was completely frozen or you noticed any damage during the storm, schedule a maintenance visit with an HVAC technician. They can check the refrigerant charge, inspect the coils for cracks, and confirm that all electrical connections are find and dry. This inspection costs less than an emergency repair call and can catch problems before they become expensive.
Frequently Asked Questions
Can I use a space heater to warm the outdoor unit and melt ice faster?
No. A space heater can damage the coils and electrical components, and it creates a fire hazard in wet, snowy conditions. Let ice melt naturally or use a plastic scraper and room-temperature water only. Forcing the ice off quickly usually causes more damage than waiting.
Should I run my heat pump continuously during an ice storm, or turn it off to save energy?
Run it normally. The heat pump is designed to cycle on and off as needed to maintain your set temperature. Turning it off entirely means you lose heating and must rely on backup electric heat, which uses more electricity. Let the system operate automatically.
What does it mean if my heat pump is making a hissing or gurgling sound during an ice storm?
Hissing or gurgling usually means refrigerant is moving through the lines, which is normal during defrost cycles. However, if the sound is loud, continuous, or accompanied by reduced heating, turn the unit off and call an HVAC technician. It may indicate a refrigerant leak or compressor problem.
How long can my heat pump run on backup electric heat if the outdoor unit freezes?
Backup electric heat can run indefinitely, but it uses 2 to 3 times more electricity than the heat pump. Use it only until an HVAC technician can inspect and repair the outdoor unit. Most repairs take a few hours to a day, so contact a technician as soon as the storm passes.
Will my heat pump work at all if the outdoor temperature drops below zero?
Yes, modern heat pumps are rated to operate in temperatures well below zero. However, efficiency drops significantly in extreme cold, and the unit may run defrost cycles more frequently. If outdoor temperatures stay below zero for extended periods, your backup electric heat may run more often, which increases your electricity bill.