May 17, 2025
With the improvement of people's living standards, the quality requirements for air source heat pumps are getting higher and higher. In this era, air source heat pumps quickly entered the market and were favored and praised by the majority of users. More and more people learned about this new product. Of course, some faults are inevitable during use. The following is an explanation of common faults and maintenance solutions for air source heat pumps by air source heat pump manufacturers.
Common faults of air source heat pumps (analysis and troubleshooting)
1. The unit just started and does not run
Check: The unit is normal, and the start-up is delayed for 3 minutes after power-on; when it is suddenly shut down and restarted during operation, it is delayed for 3 minutes
Troubleshooting: normal phenomenon.
2. Frost on the heat absorption fins of the main unit
Check: The defrost probe is faulty or (measured) whether the refrigerant content is lacking, or the capillary is slightly blocked, dirty, or iced.
Troubleshooting: Replace the defrost probe; fill the same type of refrigerant, and if necessary, vacuum it before filling, and clean the capillary.
3. The fan does not rotate and the compressor runs
Check: Is the plug between the fan and the mainboard loose? Too little refrigerant
Troubleshooting: Open the upper cover of the host and plug in the connector of the fan; Fill with the same type of refrigerant, and if necessary, vacuumize before filling.
4. The host runs but does not heat
Check: Is the refrigerant content of the unit insufficient? Is the air in the heat exchanger exhausted during installation?
Troubleshooting: Start the operation without exhausting the air in the water tank heat exchanger during installation. Fill with the same type of refrigerant. It must be vacuumized before filling.
5. The host does not run after it is turned on
Check: Is the phase sequence of the incoming power line consistent with the phase sequence of the host? Is the incoming power supply normal? Power supply failure
Troubleshooting: Connect in the standard order of "left zero and right fire", measure the incoming power supply voltage, reconnect or replace the matching power supply; find out the cause and solve the power supply failure.
6. The host is cooling but not heating
Check: Control, four-way valve setting of the display
Troubleshooting: Enter F37 of the display and change the "0" setting to "1", and power on the four-way valve to solve the problem.
7. The host is noisy
Check: Whether the installation position is horizontal, or the fan bearing is faulty, liquid refrigerant enters the compressor, and the compressor is short of refrigeration oil.
Troubleshooting: Adjust the bracket to ensure horizontal installation, replace the fan bearing, check whether the expansion valve is invalid, and add an appropriate amount of refrigeration oil.
8. The host suddenly stops rotating
Check: 1. (Summer, high-voltage protection), 2. (Winter, defrost function is activated) voltage is unstable.
Troubleshooting: 1. Avoid working during the highest temperature period and set the economic mode to run; the host defrost is normal, try to install it in the direction of the sun, and check the power supply.
9. The display shows disconnection
Check: Are the models of the main control board and the display consistent?
Troubleshooting: Replace the main control board and the display with matching models. When upgrading the control system from old to new technology, it is recommended not to use the display from other units to prevent mismatching.
10. The display does not display
Check: Are the plugs of the controller and the host properly connected? Check whether the small plug of the main control board in the host is loose or the display is faulty;
Troubleshooting: Connect the plug of the display accurately, plug the small plug of the main control board tightly, or replace the display of the same model.
11. Frequent leakage protection of the display
Check: Is the grounding wire of the incoming power line reliable? (Or the main control board is faulty)
Troubleshooting: The incoming power must be installed with a reliable grounding wire, and the main control board must be replaced.
12. Display alarm
Check: Is the connector of the signal line and the control loose or the connector is exposed to water? Is there a short circuit in the incoming power (or the main control board is faulty)?
Troubleshooting: The "three-core" plug of the signal line is accurately connected to the "three-core" socket of the main control board; the "two-core" plug of the temperature probe is accurately connected to the "two-core" socket.
13. The joint of the water tank heat exchanger is slightly leaking
Check: Whether the outer copper joint is installed in place, and whether there are welding slag particles in the bell mouth of the copper joint to cause leakage.
Troubleshooting: Loosen the copper joint in four directions and shake it slightly before tightening it; if there is still dripping, use cloth sand to lightly polish it around, straighten it and tighten it.
15: The fan does not turn and the compressor is running
Check: Whether the plug of the fan and the main board is loose; the amount of refrigerant is too small,
Solution: Open the upper cover of the main unit and plug the joint of the fan tightly; fill the same type of refrigerant, and if necessary, vacuum it before filling.
