How Does Snow Affect My HVAC System?

Presidential Heating & Air Conditioning

Gaithersburg HVAC Contractors


Share on Facebook


Tweet this


Share on LinkedIn0 shares on LinkedIn

Winter Elements Can Wreak Havoc on Your HVAC System

a heating system that was covered in snow during the winter months and needs repair from HVAC contractorsYou know that winter routine. Snow falls, it piles up everywhere, and ice covers everything. You bundle up, head outside, and start the big clean up job. While you’re out there, don’t overlook your HVAC equipment. The build-up of snow and ice on your outdoor components can cause real problems for you indoors. Here is a description of some of the common ways that the winter elements can do serious damage to your heating system, and simple steps you can take to prevent it.

Snow Accumulation

Snow and ice accumulation on your exterior equipment can require that the heating system work much harder due to limited air flow. This condition will cause your unit to short circuit and burn out earlier than it should.

When snow and ice accumulation is so heavy that it covers the outdoor equipment, it can cause the system to freeze up and trigger an emergency shut-off. This means you will have no heat in your home. Ice and snow can build up on the aluminum fan and coil fins and bend them. Bent structures can cause your HVAC unit to make strange noises while operating and can break the fins.

If your home has a heat pump, be aware that the outdoor component has a compressor and a fan that blows air across a coil to remove moisture from the air. Condensation forms on the coil and often will freeze in winter. This reduces airflow in your system, impeding efficient heat transfer. Also, because a heat pump pulls air from all sides of the outdoor unit, you must keep it clear of snow and ice. Heat pumps can run a defrost cycle when needed to remove smaller amounts of snow and ice, but too much snow and ice can overwhelm the system. Your utility bills will increase and the life of your heat pump will be decreased.

To avoid these problems, keep your outdoor HVAC components clear of snow and ice. If ice has accumulated on the equipment, avoid using ice picks, shovels, or other sharp objects to break the ice off. You can do serious damage to the equipment. Instead, try using small amounts of warm water but watch out for refreezing.

two air conditioning units that have cover from the roof of the house and therefore will not be affected by snowYou can protect outdoor units by building a cover above them to prevent ice build-up on the actual unit. Only use materials that are ‘breathable’ to avoid a build-up of condensation – i.e. don’t use a tarp or plastic sheeting – and make sure that air can still flow freely to avoid creating a fire hazard. Remove any ice build-up promptly with warm water before it gets any worse. Also, remove any snow build-up around external units to keep them operating freely.

Melting Snow and Refreezing

If you have a heavy snowfall, when it begins to melt, snow and ice can puddle around the exterior components. When the temperature drops and causes refreezing and expansion, this can cause damage. If you have a gas furnace or boiler, water from melting snow can seep into the internal valves and other components causing corrosion, malfunctioning, and even fires. When it re-freezes, your pipes may become encased in ice, which can cause your furnace to shut down.


The exterior components may be situated under a rain gutter. As icicles form on the gutter and then grow larger and larger, they become a lot heavier than you might realize. They become so heavy sometimes that they break off due to the weight. They can crash down right into your HVAC component and damage the cabinet along with the electronics and sensitive equipment inside. To prevent this damage, you should clear away the icicles hanging above your exterior equipment before they become large.

Clogged Exhaust Pipes

The exhaust pipes in your roof vent the carbon monoxide that your furnace produces when it creates heat. If snow and ice block the exhaust piping, deadly carbon monoxide can build up in your home. You should make sure your home is equipped with a working carbon monoxide detector on every floor. If you can safely access the exhaust piping in your roof, make sure it is clear of ice and snow.

How to Prepare Your Heating System for Winter

a man turning down his thermostat to allow his heating system to work during the winterOne of the most important steps you should take is to have your system inspected and serviced by a reputable HVAC contractor before the cold weather arrives. Clear away any seasonal debris before the snow falls. Clean any leaves, sticks, and other lawn debris from the top of the unit, its sides, and around its base. Cut back any adjacent shrubs and plants so that there is adequate ventilation and easy access to the units. Keep your pipes clear by covering them with insulated covering.

As always, make sure your indoor components are protected as well. While they are not directly exposed to the weather, the demands on your heating system will be higher and it will work harder. During cold months, humidity in the air is usually much lower than in the summer. Low humidity means your heating system will have to work harder as it must heat the drier air. To help keep it at optimal operating efficiency, make sure that your air filters are clear. Replace them every 30 days to ensure smooth operation throughout the winter.

Contact an HVAC Contractor for an Inspection and Service

Autumn is the time to get your HVAC system ready for the winter weather. HVAC contractors have the experience and expertise necessary to check your system, make sure it’s operating efficiently, and have it working in peak condition for the winter months. Contact a reputable HVAC contractor for a free estimate and to schedule an inspection.

Related Posts
  • Presidential Wins Nextdoor’s 2023 Neighborhood Faves Read More
  • Keep Your Cool: Seasonal HVAC Preparation for a Comfortable Summer Read More
  • 2023 Advantage Plan Membership Winner Announcement Read More