Here is a run-through of how your HVAC unit is actually affected by these chilly temperatures and how to ensure there aren't any lasting effects following into the spring and summer months.
The main issue that arises is when snow and ice encase the unit and trigger an emergency shut-off as the system freezes up. This cuts off heat to your home, which could cause burst pipes that result in significant property damage as the temperature drops.
If you have a gas furnace or boiler, melting snow can seep in and re-freeze and your pipes may become covered in ice, which can cause your furnace to shut down.
Ice and snow can build up on the aluminum fan and coil fins which will actually bend them. This can cause your HVAC unit to produce loud sounds while operating and can eventually burst the fins.
Working Twice As Hard
The snow and ice can cause the system's components to work twice as hard and limit the air flow, which can cause your unit to end up short circuiting and burning out faster than expected.
Note: Make sure to check your system's air filters regularly because a clogged filter will restrict your air flow and can cause your system to have a hard time reaching the desired temperature.
Protecting Your Home's Heating System
Clear away all debris — First, clear out any debris that has gathered around or on top of your unit.
Cover your unit — What you do to cover your unit will depend on where the unit is located. But you must ensure the air can continue to circulate near your unit or you face a fire hazard or worse. You can build a small roof over your unit or even construct an entire freestanding shelter around your unit.
Note: Keep the unit at least 18" away from the exterior wall to increase air passage and to avoid drifting exposure.
Cover all pipes — This is a very important step to take if your unit can be affected by extremely cold temperatures.
Shovel away the snow build-up — Snow buildup should be shoveled away, gutters should be inspected so they're not dripping on the unit, and ice should be melted away with warm water, avoiding ice picks and possible damage to the system.