Air energy heat pump 20 common failures you must know!

Heat pump is a kind of energy-saving device which can make heat flow from low-level heat source to high-level heat source As the low-level heat source of heat pump, air is inexhaustible and everywhere, which can be obtained free of charge Moreover, the installation and use of air source heat pump are more convenient The research, production and application of air source heat pump (also known as air-cooled heat pump) in China developed rapidly in the late 1980s At present, the products include domestic heat pump air conditioner, commercial unit heat pump air conditioner and heat pump cold and hot water unit, etc In recent years, air source heat pump technology is becoming more and more mature and widely used At the same time, after-sales maintenance problems are becoming increasingly prominent Small compilation and collection of 20 kinds of common air energy heat pump faults for your reference: 1 Fault analysis of water flow protection: water flow protection fault, common in all engineering installation Regardless of installation, there are two possibilities for water flow protection: the non circulation of water system and the damage of water flow switch itself Water flow failure is often caused by waterway problems Check and clean whether there is any problem with the pipeline filter, check whether the pipeline valve and circulating pump are damaged or open; if they are all normal, it is the fault of the water flow switch itself, which can be short circuited to see whether it is started, if it can be started, it is the problem of the water flow switch 2 Phase sequence, lack of phase and reverse phase protection Fault analysis: use a multimeter to check whether there is 380V voltage between the three-phase power supply phases of the circuit board If there is, the fault may be reverse phase protection The two adjacent incoming lines of the power supply connected to the unit can be exchanged According to experience, most of the lines are reversed; otherwise, the fault may be phase loss protection Check whether the power supply or the incoming line is reliable 3 Fault analysis of outlet overheat protection: whether the actual temperature of the water tank exceeds the set temperature; whether the water tank sensor is placed in the wrong position or the water tank sensor is not in close contact with the blind pipe wall The connection of water tank temperature sensor is broken or the resistance value of temperature sensor drifts Check the set temperature and temperature probe Check whether the water temperature value is consistent with the actual value If the temperature is consistent, replace the probe if it is broken If none of this is a problem, you need to look at the motherboard 4 Low voltage protection fault analysis: this fault is relatively common In case of this fault, the first consideration is the lack of fluorine and leakage of fluorine In addition, check whether the defrosting of the unit is poor If the unit fins are frosted seriously, check whether the fan has problems, and the fan failure will easily cause frosting And the evaporator is not cleaned for a long time, which is also prone to low pressure fault It can be tested whether the low-pressure pressure is too low under the shutdown state If it is lower than 0.5MPa, it is important to find out whether the fluorine circuit has leakage point or blockage; if it is higher than 0.5MPa, it is important to check the low-pressure protection switch and expansion valve After shutdown, use a multimeter to check whether the low-pressure switch is on If not, the pressure switch may be broken 5 High pressure protection fault analysis: confirm that the high pressure of the system is indeed too high through the pressure gauge, indicating that there is a fault in the water circuit, and these problems may exist: the actual flow of the circulating water pump is too small; the valve or filter in the water circuit is blocked; the valve is not fully opened; the water temperature is set too high; the heat exchanger is blocked by scaling; there is air in the water system; and there is water shortage in the water system If the high pressure of the system does not reach the alarm pressure, check whether the wiring of the pressure switch is reliable and plug the wiring again After shutdown, use a multimeter to check whether the high-pressure switch is on If not, the pressure switch may be broken 1 The waterway system eliminates errors in engineering installation If the unit reports high-pressure protection after normal operation for a period of time, the water quantity is often small, which may be dirty and blocked of Y-type filter or scaling of casing, which needs to be checked separately The specific steps to check whether the Y-type filter is dirty and blocked are as follows: A stop the main engine and close the valves at the front and back of the filter screen to avoid large amount of water flowing out B Use the spanner wrench to unscrew the plug of Y-type filter and pull out the filter screen C Flush the filter screen at the tap water and install it back into the pipeline D Remember to open the front and rear valves and restart If the filter screen is eliminated, the possibility of casing scaling needs to be considered Especially in some areas with hard water quality, the possibility of scaling is higher Only disassemble the water inlet and outlet pipes of the main engine to check the scaling Once it is found that the high pressure fault is caused by casing scaling, contact the professional scale cleaning master to clean it on site 2 The possibility of high-voltage protection is not high due to common unit failure of unit components It is important to check whether the fan works normally (1) If the fan does not turn, it may be the fan capacitance or the relay is broken, just adjust the multimeter to the gear or on-off gear for measurement (2) If the high-voltage switch is found to be disconnected immediately after the switch is opened and restarted, there is no doubt that the high-voltage switch itself is broken Replace one (3) If the unit has been used for many years, the fins are covered with dust, which may also cause high-pressure protection, and the fault can be eliminated only by cleaning with water 6 Fault analysis of water level switch: common causes are reverse connection of high and low water level; poor connection of low water level device; main board fault 7 Communication fault analysis: check whether the shield wire is disconnected in the middle of the process and whether the two ends are in poor contact when they are plugged in If the disconnection contact is poor, the fault point can be determined by re plugging and replacing the control panel, shielding wire and circuit board In addition, if the communication wire is not copper core wire, or the control board is damped, communication failure may occur 8 Fault analysis of over high exhaust temperature protection: when the unit is running, check whether the exhaust temperature value is consistent with the actual temperature, and check whether the exhaust temperature exceeds 120 ℃ The exhaust temperature is not high The exhaust temperature sensor may be damaged, the contact may be poor or the circuit board may be damaged If the exhaust temperature is too high, check whether the high and low pressure are normal, whether the expansion valve is slightly blocked, whether the unit is lack of fluorine, whether the four-way valve is connected, whether the compressor is connected, and whether the refrigerant pipeline is blocked 9 The temperature sensor is faulty Fault analysis: first, check whether the connector of the probe on the main board side is secure and whether there is any problem on the main board If there is no problem, it indicates that the corresponding temperature sensor is either short circuited or open circuited Check the resistance of the corresponding sensor probe When the temperature is 25 ℃, the normal resistance of the sensor is about 5K Ω (the exhaust temperature sensor is 80 ℃, 50K Ω) If the resistance value is normal and it is not OK after re plugging and confirming, it can be judged as circuit board fault 10 Failure analysis of the main engine not running: first, make sure that the parameters of the unit are set correctly, and then check whether the power supply is faulty; check whether the compressor contactor is faulty, and whether the wires are tight In addition, if the compressor operates at high load for a long time, overheating protection will occur 11 Failure analysis of water pump not starting: judge whether the water pump is stuck It is very difficult to touch the pump by hand or turn the fan blade with a screwdriver to prove that the pump shaft is stuck The treatment method is to turn the pump fan with a slotted screwdriver The water pump shaft needs to be replaced or repaired The main board water pump has no output signal Use the voltage range of the multimeter to directly measure whether the load port of the water pump has output No output proves that the main board has problems Just replace the main board If the water pump relay is burnt out, use the ohm gear of the multimeter to measure the normally open port of the water pump relay When the measured resistance value is infinite, it is proved that the relay is damaged Of course, it can be judged whether it is burnt out by visual inspection Only one relay needs to be replaced to make the water pump operate normally 12 No display fault analysis on the display screen of control panel: check whether there is no power, check whether the fuse of the equipment is blown normally If these are all normal, check whether there is a problem on the main board or the display 13 Fault analysis of low outlet water temperature: 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 water tank temperature value is consistent with the actual value (if the water tank temperature control machine works), check and clean the pipeline filter, check whether the pipeline valve is damaged and open, and check whether the circulating pump meets the flow requirements of the unit, yes No normal operation 14 Air switch trip fault analysis: if the air switch fails to close, replace an air switch and ensure that the line is not connected falsely If not, it may be that the compressor is grounded or there is a short circuit on the main board After accurate judgment, replace the compressor or the main board Air switch occasionally trips, which is often caused by the virtual connection of air switch line It is important to check whether the line is firmly connected Of course, if the air opening is in a place with high humidity, it may be affected by damp, which may cause tripping 15 The heating capacity is low Fault analysis: poor heat dissipation of air heat exchanger, cleaning of air heat exchanger; insufficient water flow, cleaning of filter; insufficient refrigerant injection, leakage detection and injection of quantitative working medium; fan motor failure, severe frosting of evaporator; poor insulation of pipeline, re insulation of pipeline; blocking of unit refrigerant system, detection of blocked components; compressor problems, replacement of compressor 16 Failure analysis of unclean defrosting: the coil probe falls off, check whether the temperature sensing position of the coil probe is accurate and damaged; the defrosting parameter setting is inaccurate, readjust the defrosting parameter; the system is lack of refrigerant 17 Analysis of fan non rotating fault: the fan motor is burnt out, replaced or repaired; the contactor is broken, replace the contactor; the fan capacitance is broken, replace the capacitance; there is no start signal, and the main board fan has no start signal 18 There are many reasons why the compressor doesn't start when there is no problem in the water system For example, the AC contactor of the compressor is stuck, the main board has no output, the compressor is stuck, the compressor overcurrent protection and so on Therefore, we need to clear a thought step by step to investigate the reason why the compressor does not start Step: if the compressor trips as soon as it is started, it is often caused by compressor cylinder jamming or compressor grounding Step 2: check whether there is output at the load of the main board compressor, then check whether there is output at the AC contactor of the compressor, then check whether there is output at the terminal of the compressor, check one by one until the cause is found When the panel reports compressor over-current protection, the compressor does not start due to low voltage, so it is necessary to detect whether the user's home voltage is normal 19 The failure of the wire controller includes the black screen of the wire controller, the communication failure reported by the wire controller and the insensitivity of the wire controller (1) Remote control black screen The general troubleshooting steps for the black screen of the line controller are as follows: first, confirm whether the unit is powered, and then try to replace a new line controller After it is still not lit, focus on checking whether the main board of the unit has output If there is no output, it may be the main board transformer is damaged or the main board fuse is burnt out, just replace one Of course, this situation needs to be observed later to eliminate the load short circuit and avoid the configuration The parts are damaged twice (2) The line controller reports the communication failure and reports the communication failure Check whether the wiring is connected falsely If not, it is often the voltage problem Focus on whether the voltage is abnormal (3) The wire controller is not sensitive If the wire controller is just used, it is not sensitive The internal wiring may touch the key If the wire controller is not sensitive after a period of normal use, it may need to be replaced 20 There are many temperature sensing head interfaces on the main board of temperature sensing head fault unit, which are used to detect all kinds of temperature parameters required by the system, such as exhaust temperature sensing, return gas temperature sensing, coil temperature sensing, etc Once the panel shows the temperature sensing fault, it is necessary to focus on the troubleshooting of the corresponding temperature sensing head