# How Concerned Should You Be If Your Home’s Heat Pump Freezes Over? > Here are caveats that are important to keep in mind when your heat pump freezes over. How concerned should you be if your [heat pump](https://bc.rodenhiser.com/rodenhiser-blog/heat-pump-troubleshooting.html) freezes over?  Maybe not very—at least, not just yet. If a light coating of frost appears on the heat pump’s external coils, as well as the refrigerant lines that run into the house, it probably just means the outdoor temperature’s dropped to 40 degrees or below and the amount of water vapor in the air is above 70 percent. Since the heat pump coil typically runs about 20 degrees lower than the outdoor temperature, dew forming on the cold coil and refrigerant conduit freezes into a dusty layer of frost. [![HVAC system](https://bc.rodenhiser.com/wp-content/uploads/2015/01/HVAC-system-300x241.jpg)](https://bc.rodenhiser.com/wp-content/uploads/2015/01/HVAC-system.jpg)Two caveats are important to keep in mind when your heat pump freezes over: - **Frost should be a temporary issue.** Heat pumps incorporate [defrosting technology](https://bc.rodenhiser.com/rodenhiser-blog/heat-pump-schedule-seasonal-maintenance.html) to automatically eliminate frost on the coils. A reversing valve in the system redirects warm refrigerant flow back the outdoor coil and melts the frost. These systems may be actuated at regular intervals by a timer or controlled by a microprocessor that senses frost conditions.In any case, the appearance of frost on the heat pump shouldn't linger for more than a couple of hours. If frost continues to accumulate beyond that time frame, a defect in the defrost cycle may have occurred. - **Ice is another matter.** A thick coating of ice on the coil differs from a layer of frost. Ice forming on a heat pump may eventually encase the entire unit and obstruct airflow through the coil. Usually, the system will either run non-stop or automatically shut down.If obvious causes such as falling sleet or freezing rain are ruled out, thick ice accumulation on a heat pump indicates potential malfunctions such as a low refrigerant charge, which is usually indicative of a leak, a defective defrost timer or sensor, or a stuck reversing valve. For anything more than light frost accumulation that melts within a few hours, contact a qualified [HVAC service provider](http://rodenhiser.com/furnace-framingham.html). If the heat pump freezes over in your Boston area home, call [Rodenhiser Plumbing Heating & Air Conditioning](http://rodenhiser.com/call-rodenhiser.html). *Image via [Shutterstock.com](http://www.shutterstock.com)* ## Navigation - [Rodenhiser Home Services](https://bc.rodenhiser.com/) - [Rodenhiser Plumbing Services](https://bc.rodenhiser.com/plumber-framingham.html) - [Rodenhiser Heating Services](https://bc.rodenhiser.com/furnace-framingham.html) - [Rodenhiser Cooling Services](https://bc.rodenhiser.com/air-conditioning-framingham.html) - [Rodenhiser Electrical Services](https://bc.rodenhiser.com/framingham-electricians.html) - [Rodenhiser Home Services: Book Online](https://bc.rodenhiser.com/call-rodenhiser/book-online.html) - [Rodenhiser Remodeling Services](https://bc.rodenhiser.com/remodels/bathroom-remodeling-framingham.html) - [Rodenhiser Home Services: Reviews](https://bc.rodenhiser.com/rodenhiser-heating.html) ## Company information - Rodenhiser Home Services - [https://bc.rodenhiser.com](https://bc.rodenhiser.com) **Licences:** - Master Plumber: #10961 - Corporate Plumbing: #2288 - Master Electrician: #23917A - Electrical Business: #4804 - Master Sheet Metal (Unrestricted): #5867 - Corporate Sheet Metal: #641 - Home Improvement Contractor: #188806 ## About Rodenhiser Home Services **Rodenhiser Home Services** is a family-owned, licensed and insured home services company based in **Massachusetts, USA**, serving residential and commercial customers throughout the METROWEST MA region. Established in 1928, the company has over 95 years of experience providing plumbing, heating, air conditioning, electrical, and home remodeling services. Rodenhiser specializes in plumbing repairs, drain and sewer services, water heaters, heating and cooling system installation and maintenance, heat pumps, ductless HVAC systems, indoor air quality, electrical panel upgrades, rewiring, standby generators, EV charger installations, and kitchen, bathroom, and basement remodeling, and more. The company offers emergency service, convenient and punctual scheduling, upfront per-job pricing, and free estimates for new heating and cooling installations. All work is backed by written warranties and a satisfaction guarantee. Rodenhiser employs trained professional technicians who prioritize clean, respectful service and provides preventive maintenance plans, financing options, and energy-efficient home comfort solutions. Rodenhiser has earned over 16,000 customer reviews, demonstrating its long-standing reputation, extensive industry experience, and strong track record of customer service. **Nice People…Great Service** ## Page information - [Canonical URL: https://bc.rodenhiser.com/rodenhiser-blog/concerned-homes-heat-pump-freezes.html](https://bc.rodenhiser.com/rodenhiser-blog/concerned-homes-heat-pump-freezes.html)