Reasons for Frosting and Defrosting Method of Air Source Heat Pump

In winter, because of the low temperature, it is normal for the evaporator of the air source heat pump to frost, but if the frost does not frost properly, or even freeze, it will seriously affect the heating effect. Next, let's take a look at the causes and defrosting methods of air-source heat pumps.

Here is the content list:

• Frost at the bottom of the air source heat pump evaporator

• The air source heat pump evaporator on both sides of the uniform frost has not been defrosted

• Incomplete frosting

• Short time frequent frosting

• The air source heat pump evaporator partially frost

• High-pressure protection in the process of defrosting

• Low-pressure protection during defrosting

• Frosting even if there is no frost

Frost at the bottom of the air source heat pump evaporator

Most of them are caused by poor drainage of the water accumulation tray. After using hot water to artificially defrost, clean up the dirt and keep the water accumulation tray draining smoothly. It should be noted that if you find frost on the evaporator of the air source heat pump, don't use hard things to remove it, it is easy to cause damage to the copper tube and even refrigerant leakage, the best way is to use hot water to shower.

Air source heat pump evaporator on both sides of the uniform frost, and has not been defrosted

① Check the frost temperature, or air source heat pump host frost probe placed in the frost body, 3 minutes the frost temperature is shown in more than 5 ℃, you can determine the frost probe failure, hot water shower, artificial frost, replace the frost probe can be.

② If the compressor works normally, the four-way valve for reversing operation, or directly to the four-way valve power, if there is no sound of the four-way valve suction, nor do you hear the sound of refrigerant flow, you can determine the four-way valve coil is broken; if there is the sound of suction, but no sound of refrigerant flow, it is because the four-way valve stuck open, can not be reversed, resulting in air source heat pump evaporator frost, this time need to replace the four-way valve.

Incomplete frosting

After the frost can be frost, but the frost is not clean, not complete, or one side of the frost, one side of no frost. This situation is generally due to.

① The frost end temperature setting is too low or the frost time setting is too short, adjust the frost end temperature and frost time appropriately;

② If the position of the frost probe is not reasonable, then the frost probe can be placed in the most serious place of frost.

Short time frequent frosting

① Check whether the frosting temperature is normal, if the frosting temperature is normal and below 0℃, check whether the ventilation around the host is good, clean the debris around the host and clean the evaporator, and extend the frosting time and increase the frosting end temperature appropriately.

② Air source heat pump host frequent frost and the pressure gauge pressure is low, first artificial frost with hot water, and then observe the low-pressure gauge when heating, if the pressure is lower than the normal value (can be compared to similar models), you can determine the refrigerant is insufficient or refrigerant leakage.

③ Host fan motor damage or insufficient air volumes, such as blade damage, or fan motor power is small.

Air source heat pump evaporator partial frost

Air source heat pump evaporator side or both sides of uneven frost or part of the area frost, this situation is caused by the uneven distribution of refrigerant, mostly for a way the capillary tube is not smooth or ice blockage, the exclusion method is to move the frost probe to the first frost and not easy to frost copper tube or replace the capillary tube, re-vacuum, add refrigerant.

High-pressure protection in the process of defrosting

This is due to the air source heat pump end defrost temperature setting being too high, appropriate adjustment of the end defrost temperature can be, generally set to 10 ℃.

Low-pressure protection during defrosting

This is caused by the blockage of the throttle expansion valve in reverse or the opening of the throttle expansion valve being too small, it is necessary to replace the throttle expansion valve or mediate the opening of the throttle expansion valve.

Frosting even if there is no frost

This is because the starting frost temperature is set too high, or the frost probe is bad, resulting in the machine's misoperation. At this time, you only need to adjust the frosting start temperature or replace the frosting probe.

The above is about air source heat pump frost causes and defrosting way. If you are interested in an air-source heat pump, you can contact us at https://www.laileyheatpump.com/.