Winter is coming, 8 kinds of situations and solutions for air source heat pump evaporator frost
It's the season when the after-sales personnel of air source heat pump manufacturers and middlemen are the most uncomfortable once again. Dear frontline staff, are you ready? In winter, it is normal that the air source heat pump evaporator will frost. The unit will automatically frost, which is just by absorbing the temperature in the water tank or changing the cooling mode. But we are people who want to popularize the knowledge of air source heat pumps with everyone, so what we want to say here is what to do if the air source heat pump unit fails to defrost normally after frosting, or even freezes, which seriously affects the heating effect. Usually the judgment steps and elimination methods of the master are as follows:First check whether the settings are correct, whether the defrost start time, start temperature, defrost time, defrost end temperature and other settings are reasonable. Under normal circumstances, the factory-set start temperature of defrosting is 2-4℃, the defrosting time is 30-45 minutes, and the end temperature of defrosting is generally about 10℃. First check whether these settings are reasonable, and then proceed to the next step of judgment.
The frosting of the air source heat pump evaporator is usually divided into the following 8 situations
1. Frosting on the bottom of the evaporator
Most of them are caused by poor drainage of the water pan. After artificial defrosting with hot water, clean up the dirt and keep the water pan drainage unblocked. It should be noted that if the evaporator is found to be frosted, do not use hard objects to remove it, which may cause damage to the copper pipe or even leakage of refrigerant. The best method is to use hot water to shower.
2. Both sides of the evaporator are evenly frosted and never defrost
1) Check the defrosting temperature, or place the defrosting probe of the main engine in the frost body. After 3 minutes, if the defrosting temperature is above 5℃, it can basically be determined that the defrosting probe is faulty. Use hot water to rinse and artificially After frosting, replace the defrosting probe.
2) If the compressor is working normally, the four-way valve is reversing operation, or the four-way valve is directly energized. If there is no sound of the four-way valve sucking in, and no sound of refrigerant flowing, it can basically be determined that the four-way valve The coil is broken; if there is a sucking sound, but there is no sound of refrigerant flowing, it is because the four-way valve is stuck and cannot be opened, and the evaporator is frosted. At this time, the four-way valve needs to be replaced.
3. It can defrost after frosting, but the defrosting is not clean and incomplete, or there is frost on one side and no frost on the other side. The solution to this situation is:
1) If the defrost end temperature is set too low or the defrost time is set too short, it is enough to adjust the defrost end temperature and defrost time appropriately;
2) The position of the defrosting probe is unreasonable. At this time, the defrosting probe can be placed in the most severely frosted place.
4. Frequent frosting in a short time
1) First check whether the defrosting temperature is normal. If the defrosting temperature is normal and below 0℃, first check whether the ventilation around the host is good, clean the debris around the host and clean the evaporator, and appropriately extend the defrosting time and increase the defrosting End temperature.
2) The host frequently frosts, and the pressure of the pressure gauge is low. First use hot water to artificially defrost, and then observe the low pressure gauge during heating. If the pressure is lower than the normal value (can be compared with similar models), it can basically be judged as a cooler Insufficient, or leakage of refrigerant.
3) The main engine fan motor is damaged or the air volume is insufficient, such as the blade ring is damaged, or the power of the fan motor is too low.
5. Uneven frosting or partial frosting on one or both sides of the evaporator
This situation is caused by the uneven distribution of the refrigerant, mostly caused by a capillary tube being blocked or blocked by ice. The elimination method is to move the defrost probe to a copper tube that is frosted and difficult to defrost or replace the capillary tube and re-pump it. Vacuum and add refrigerant. For example, when the air source heat pump is running, frost is formed from the liquid distribution head to the evaporator and the evaporator near the liquid distribution pipe. That should be caused by insufficient refrigerant or refrigerant leakage. Vacuum and add refrigerant.
6. High pressure protection occurs during defrosting
This is because the end defrosting temperature is set too high, just adjust the end defrosting temperature appropriately, generally set to 10℃.
7. Low pressure protection occurs during the defrosting process
This is caused by blockage or too small opening when the throttle expansion valve is reversed. At this time, it is necessary to replace the throttle expansion valve or adjust the opening of the throttle expansion valve. The specific adjustment method is detailed in the manufacturer's manual. Explain that the parameters adjusted by different models are not the same, so I won't do too much description here.
8. Defrosting without frosting
This is because the starting defrosting temperature is set too high, or the defrosting probe is broken, causing the machine to malfunction. At this time, only need to adjust the defrost start temperature or replace the defrost probe.
Leomon is a professional manufacturer of air source heat pumps. If you have other unsolvable problems. Please contact Leomon in time. We will give you the most professional answer
