It is normal for heat pumps to ice up during the winter season. You may notice the entire coil to be covered in light frost in extreme weather conditions.
You should call an HVAC professional if you notice the entire unit encased in ice for a long time. If there is ice on the top of the unit, and the insides of the coil, you have a problem in your hands.
Calling the pros for a diagnosis can help you save energy and avoid severe damage to the unit.
All heat pumps contain refrigerant, which is several degrees colder than outdoor air. If this temperature dips below the dew point and freezing point, frost can develop on your heat pump.
Heat pumps will ice-up naturally during the winter but will enter into a defrost cycle to remove ice from the coils. If the coils are frozen, proper heat transfer between the outside air and refrigerant can’t happen.
In a worst-case scenario, you can have your fan blades damaged, coils crushed, and refrigerant leaks, which lead to a damaged compressor.
Understand the Causes of Frozen Heat Pumps From HVAC Professionals
If a heat pump gets frozen during winter, there’s a chance it’s not defrosting.
Older model heat pumps have mechanical timers that work with a defrost thermostat.
This means that a unit will go into defrost mode no matter if it’s iced up or not. When the thermostat reaches a specific temperature, defrost is terminated.
Newer models use solid-state control modules that have temperature sensors. More advanced units have the Demand Defrost system, which calculates the outside air, run time, and refrigerant temperature in the coil.
HVAC professional can determine the cause of your frozen heat pumps, which may be caused by the following:
- Restriction due to leaves or snow
- Damaged outdoor fan motor
- Low refrigerant charge
- Sticking reversing valve
- Damaged defrost control or timer
- Broken sensor or defrost thermostat
- Damaged defrost relay
- Broken reversing valve solenoid coil
- Freezing rain
- Leaking gutter
- Need elevation or leveling
The defrost function of heat pumps are needed in cold weather. This prevents your heat pump from icing completely.
To save energy, defrost cycles run only when needed. These cycles usually last 10 to 15 minutes, depending on weather conditions. Heat strips start up and keep the air warm. They work until the unit unfreezes.
These cycles are usually enough to keep your unit running efficiently all winter long.
Frozen Heat Pumps Common Fixes
Heat pumps are considered the most efficient alternative to oil, fuel, and electrical systems when it comes to cooling and heating. Efficiency ratings can go up to 300%.
Choosing a heat pump that can work efficiently during the colder months is essential as some units experience trouble during winter.
You should not get alarmed if your heat pump appears to be frozen over because it is completely normal. Just wait for your pump to go into defrost mode, and you are good to go.
Excess ice, however, can cause damage to your HVAC system and may cause your unit to stop completely.
If your heat pump is not defrosting, there are a few fixes you can apply. Check if your filter is in good condition. Dirty filters can cause problems, so replace one that is full of buildup.
Next, you should inspect the fins of the condensing fan. Clear it from leaves or debris that may be blocking the unit.
Turn the fan manually, if no air comes out of the blower vents, you may have a blower motor problem that needs attention.
Inspect for gutters that are overflowing and pouring out into the outside unit. Repair your gutter and make sure no dripping will occur.
If your heat pump has settled into the ground, you should elevate it by using blocks.
Remove any ice that has accumulated on top of your outdoor unit. Using a garden hose to melt the ice is better than jabbing the ice with a sharp object. Clear excess snow that has built up around your unit.
Fan coils are delicate pieces of equipment that can be damaged easily. Never use a sharp or pointed object to chip away ice from the coils.
If you need assistance, you can call your HVAC professional to perform a diagnosis of your heat pump.
Conclusion
For climates that require moderate heating and cooling, heat pumps are an excellent alternative to furnaces and air conditioning units. They function much like your refrigerator by using electricity to move heat from a cool space to a warm place.
Heat pumps can provide equal space conditioning at one-quarter of the cost of conventional heating and cooling equipment.
As winter approaches, heat pumps are at the center of activities once more.
You don’t have to panic when you see your heat pump covered in frost. In most cases, this is normal, so you don’t have to worry about that huge repair bill that you are anticipating.
Heat pumps are designed to handle the ice buildup that occurs during winter. If the unit detects ice buildup, it will automatically enter into defrost mode.
In normal conditions, your heat pump switches to air conditioning mode for a couple of minutes. This process heats the outdoor coils for melting any frost that has built up.
A little frost on your heat pump is no big deal. As long as it melts after a few hours, then you’re all good.
On the other hand, a thick layer of ice that stays on your heat pump is no small matter.
Defrost cycles last from 5 to 15 minutes. If your heat pump is still frozen after 30 minutes, you better call your HVAC contractor for an inspection.
If your heat pump is having repeated issues, it may be time to upgrade to a new system. HVAC service providers can give you the best recommendations so you can make the best decision with your new unit.
