20 common faults and repair methods of air source heat pump heating system
In recent years, air source heat pump heating projects have blossomed everywhere in the northern region, and their application fields have become wider and wider. However, since heat pump heating has not been promoted in the north, engineering companies lack sufficient technology and experience for such projects, so that when the air source heat pump fails, many people will be at a loss what to do.
In the heat pump class, many years of experience in heat pump heating projects were summarized and shared, and the common faults and problems of air source heat pump heating projects were listed and how to solve them.
Air source heat pump fault code fault and treatment
1 ) Phase sequence
fault Cause of fault: The power provided by the host does not match the host. If the compressor is reversed, it is easy to be burned out, so it is necessary to install a phase sequence protector. How to judge the situation? Under normal circumstances, the fault code "LELL3" will be displayed directly on the display board .
first check whether the wiring of the power supply voltage line is correct;
if the problem is not resolved, it may be that the phase sequence board is broken, just replace the phase sequence board.
According to experience, most of the wiring is reversed, and it is rare to have a problem with the phase sequence board hardware, because the new machine is generally strictly tested.
2 ) Water flow switch failure
Cause of failure: The small water flow cannot close the water flow switch, resulting in failure to start the machine.
If there is a failure after running for a period of time, first check and clean the pipeline filter (the new machine does not need to be checked);
check whether the pipeline valve is damaged or whether it is open;
check whether the circulating pump meets the flow requirements of the unit;
the water pump in the new machine debugging Whether it is reversed;
if it is normal, then the water flow switch itself is faulty and needs to be replaced, or directly short the two wires of the water flow switch on the main board, if it starts, it must be the problem of the water flow switch.
3) Water inlet sensor failure
Cause of failure: Also called return water sensor failure, the motherboard cannot detect the inlet water temperature or the detected value exceeds the limit value.
If the cable is not connected properly, you need to check whether the probe circuit is damaged or not, and check whether the connector on the main board side is firm; if there is a
problem with the sensor failure itself, replace the water inlet temperature probe;
if the main board is broken, the water temperature will not be detected. Replace the main board.
4 ) High-voltage switch failure
Cause of failure: The high-pressure measurement pressure of the unit is too high and exceeds the design value, and the pressure gauge exceeds the yellow line. When it reaches the red line immediately, a high-pressure failure will occur.
Consider the lack of water flow, check and clean the pipeline filter;
check whether the pipeline valve is damaged or whether it is open, the valve with poor quality may not be opened properly, resulting in insufficient water flow, and the heat of the machine cannot be exchanged. High-pressure alarm;
check whether the circulation pump meets the flow requirements of the unit and whether it is running normally;
check whether there is scale inside the water inlet and outlet of the machine. If there is scale, the heat generated by the compressor cannot be exchanged, and high-voltage failures are prone to occur.
Low-voltage switch failure
Cause of failure: This failure is relatively common, that is, the low-voltage pressure is too low, and the low-voltage switch will be disconnected at this time.
Check whether the unit is short of fluorine. When encountering this kind of failure, the first consideration is the lack of fluorine and leakage of fluorine, because the electronic expansion valve and other components are damaged or the equipment is shaken to crack, and the welding process of the copper pipe is not good, which will lead to leakage. Fluorine, a low-pressure alarm occurs;
check whether the fins of the surface cooler are blocked, if the fins are dirty, or the surface of the evaporator is seriously blocked, low-voltage faults are likely to occur, then in the north, beware of catkins attached; check whether the fan is running normally
, If the fan does not operate normally, it will easily generate frost, especially in winter, which will cause the failure of the low-voltage switch.
6 ) Outlet water temperature is too high
Cause of failure: Outlet water temperature exceeds the set value, which happens occasionally.
Check the probe and its related parts;
check whether the outlet water temperature value is consistent with the actual value, check whether the temperature value of the water tank is equal to the actual value, you can directly touch it with your hands, if the temperature is consistent, then the probe is broken and replaced Probes are fine;
check and clean the pipeline filter;
check whether the pipeline valve is damaged and whether it is open;
if the valve is not damaged and is open, check whether the circulating pump meets the flow requirements of the unit and whether it is running normally
. If all of the above are normal, you need to check Check the motherboard to see if there is any problem with the motherboard.
7 ) Communication failure
Cause of failure: The display board cannot receive data from the main board.
In the case of normal installation, the controller installation will be moved to the house or a place that is easy to observe, and the cable needs to be extended, so it is necessary to check whether the extension cable is damaged; check whether the display signal cable
connector is firmly connected;
Check whether the wiring on the back of the display is loose or not,
and check whether there is any problem with the display board. Generally speaking, the display board has two signal wires and two power wires. If the distance between the wires is very long, the power provided by the controller is insufficient, and the display board is prone to flickering. Add a transformer to the position to ensure power supply, and the display will be normal.
8 ) Coil sensor failure
Cause of failure: The main board cannot detect the coil temperature or the detected value exceeds the limit value. If the coil is faulty, it will cause inaccurate defrosting, which will have a great impact on defrosting in winter.
Check whether the probe circuit is damaged;
replace the coil temperature probe, and check whether the probe’s connector on the main board side is secure; the sensor
itself is not faulty, and the circuit is not loose, then there is a problem with the main board, just replace the main board.
9 ) Exhaust sensor failure
Cause of failure: The motherboard cannot detect the exhaust temperature or the detected value exceeds the limit value, or the exhaust temperature detected when the unit is in working condition is lower than 10°C . This kind of failure generally rarely occurs. In winter, if there is fluorine leakage or various reasons cause the system to fail and the machine does not work, and the ambient temperature is lower than 10°C , then it will report a failure of the exhaust sensor.
Check whether the connector of the probe on the motherboard side is secure;
check whether the exhaust temperature value is consistent with the actual temperature, if not, check whether the probe line is damaged, and replace the coil temperature probe; if it is
consistent with the actual temperature, check the unit Whether the compressor works normally during work;
check whether there is any problem with the motherboard.
10 ) Antifreeze protection Cause of failure: The ambient temperature is lower than the antifreeze set value, and the antifreeze cycle is started to prevent freezing damage to the equipment. When a single machine stops working in winter, antifreeze is very important. It must be activated when the temperature is 3°C lower than the ambient temperature , otherwise the water pump, pipes, and machine may be damaged by freezing. If the water pump is frozen and the antifreeze protection has not been activated, the water pump is easy to burn out, so the antifreeze protection is very important for single machine installation. Solution: check whether the ambient temperature value is consistent with the actual value, if it matches, it is normal, if it does not match, you need to replace the probe. 11 ) Exhaust temperature is too high Cause of failure: The exhaust temperature detected by the host is higher than the limit value ( 125°C ). Solution: check whether the exhaust gas temperature value is consistent with the actual temperature, if not, replace the coil temperature probe; if it is consistent with the actual temperature, check the operation of the unit, check whether the fins of the surface cooler are blocked, check whether the unit is short of fluorine, Whether the four-way valve is blown, whether the compressor is blown, and whether the refrigerant pipeline is blocked. 12 ) Outlet water temperature is too low Cause of failure: The main board detects that the outlet water temperature is lower than the limit value ( 3°C ), which will cause insufficient head flow of the pump. Solution:
Check whether the outlet water temperature value is consistent with the actual temperature, if not, replace the outlet water temperature probe; if it is consistent
with the actual temperature, check whether the temperature value of the water tank is consistent with the actual value (if the water tank temperature control machine is working), check and clean the pipeline filter , Check whether the pipeline valve is damaged and whether it is open, check whether the circulating pump meets the flow requirements of the unit, and whether it is operating normally.
13 ) High temperature protection
Cause of failure: The system detects that the water temperature exceeds the upper limit of temperature control ( 60°C ).
Check whether the temperature value of the water tank is consistent with the actual value (if the water tank temperature control machine is working), if the actual temperature exceeds the upper limit of the temperature control, check whether other heat sources are turned on normally, if normal, the fault will automatically recover when the temperature drops. If the checked value does not match the actual value, replace the temperature control probe.
Generally, in practical applications, solar energy and air energy are more combined now. In summer, when the temperature of solar water heating exceeds the set upper limit, high temperature protection will appear. When the temperature is lower than this set value, it will be automatically eliminated. Worry about the alarm that comes out of the high temperature protection.
Faults without fault codes and their treatment
14 ) The heating capacity of the unit is reduced
. The cause of the fault: the heat absorbed by the unit is reduced, the heat exchange efficiency is reduced, and the heat loss of the system is serious.
check whether the fins of the surface cooler of the unit are dirty and blocked;
check whether the exhaust air of the unit is not smooth, such as the fan does not turn, the fan blade is damaged, and the location of the unit is not well ventilated
; No aging, whether the water flow is reduced;
poor insulation of the pipe, aging of the insulation pipe or long pipe will reduce the insulation effect.
15 ) The compressor does not run
Cause of failure: everything is normal (the display does not prompt the compressor to fail). Then there are five possible reasons for the failure : power failure, damage to the compressor contactor, disconnection of the compressor protector, loose wiring of the compressor, and overheating protection of the compressor during long-term high-load operation.
Check whether the power supply voltage is normal, check the AC contactor, protector and wiring;
check whether the motor part of the compressor is very hot, if it is overheated, it means that the compressor has been working for too long and the load is too large, it needs to be cooled down and the reason should be checked.
16 ) Causes of high noise during compressor rotation: The main reasons for this part are: the compressor only compresses gas but not liquid, and the liquid refrigerant enters the compressor; the internal parts of the compressor are damaged; the compressor has insufficient refrigeration oil or poor oil return ( gas
There is a problem with the liquid separator, and the liquid is not divided thoroughly).
Check whether the expansion valve is out of order;
replace the compressor;
add an appropriate amount of refrigeration oil to make the compressor lubricate better;
check whether there is any blockage in the refrigerant system.
17 ) The fan does not turn.
The cause of the failure: no start signal, the capacitor may be broken or the fan may be burnt out.
Check whether the starting signal of the fan on the motherboard is normal and whether there is output;
whether the AC contactor is intact;
check whether the capacitor is loose, or the capacitor is bulged and replace the capacitor;
replace the motor.
18 ) The compressor is running but the unit does not heat (refrigerate) Fault
reason: This fault is difficult to occur, unless [heat pump market watermark] all faults of low pressure and high pressure fail, this fault will occur. The main reasons are refrigerant leakage, refrigerant system blockage, and compressor failure.
check for leaks, repair leaks and fill refrigerant;
check for clogged parts;
replace the compressor.
Causes of high exhaust pressure (high pressure gauge) : The main reasons are insufficient water flow, scaling of heat exchanger, excessive refrigerant, and air in the refrigerant system.
check and clean the pipeline filter, check whether the pipeline valve is damaged and whether it is open, check whether the circulating pump meets the flow requirements of the unit and operates normally; clean the scale; let go of
20 ) Low suction pressure (low pressure gauge)
Causes of failure: The main reason is that the fins of the surface cooler are dirty, the fan exhaust is not smooth, the refrigerant is insufficient and leaked, the refrigerant system is blocked, or the opening of the expansion valve is small.
clean the surface cooler;
repair the fan and remove obstacles;
check for leaks and add refrigerant;
check and replace blocked parts, and adjust the expansion valve.
The high exhaust pressure or low suction pressure depends on the engineers and maintenance personnel to find out in advance. When the high pressure and low pressure alarms are not reached, there will be some precursory phenomena for observation, such as insufficient water flow, heat exchanger Scaling, etc., through early prediction to deal with high pressure and low pressure conditions in advance.