Heat Pump Defrost Cycle

When the outside temperature is below 42 degrees it is common for a heat pump to have some ice buildup, and have a need to be defrosted. Many of our clients are not familiar with this process. The following is what you can expect to experience during a defrost cycle:

Outside.
1. You may or may not hear a loud swishing noise as the system goes into and out of the defrost cycle.
2. Compressor can sound louder than normal.
3. The outdoor fan motor will shut off during the defrost cycle.
4. As the outdoor unit defrosts, you may see steam from the unit.
5. The machine will shed water onto the roof and or ground by the unit. This water is distilled & will not harm the roof;

Inside.
1. Its normal to feel cold air coming through the supply vents during a defrost cycle (unit in a/c mode)
2. During defrost, Do Not Turn off the thermostat this can delay the defrost cycle. As it can last up to 20 minutes long.
3. Thermostat may drop a few degrees depending on the length of the defrost cycle (this is normal).
4. After system has gone thru a defrost cycle, it will return to heating.

Heat pumps are great at maintaining a temperature but will not raise temperature in the house as rapidly as a gas or electric furnace.

During the cold winter nights and mornings it is best to keep your thermostat at a consistent comfortable temperature. We recommend between 69-72 degrees. The key thing to remember about your heat pump is SET IT AND FORGET IT.

What you should know about your heat pump: gas furnaces heat a house by burning natural gas. They create the same amount of heat whether the outdoor temperature is 70F or 30F because they have a continuous fuel source available to them from the gas company. Electric furnaces are similar in that they also have a constant source of electrical power to create heat. Heat pumps are favored over electric furnaces because they are at least 3 times more efficient but they operate differently than gas or electric furnaces. The heat source that a heat pump uses to warm your house comes from the outdoor air. Consequently the colder the air is outside the less heat is available for your heat pump to do its job. Because of this difference in operation a heat pump has plenty of capacity to heat your house if it is allowed to maintain a steady indoor temperature. If you set your thermostat to a lower temperature or turn your heat pump off at night the next morning it may have difficulty raising the temperature of your house. As an example if you allow your house to drop 10 degrees during the night and then turn your thermostat up 10 degrees the next morning it could take hours for you heat pump to bring the house back up to a comfortable temperature and it will be operating when it is least efficient. Leaving your thermostat set at a constant temperature will allow your heat pump to maintain a comfortable environment and operate at it’s peak efficiency.