Danfoss Heat Pump Troubleshooting Guide

Technical documentation | Air and ground source heat pumpsLooking for support? Heat Pump Troubleshooting GuideError phase sequence 02Working presso

10VMIFB202Phase drop or blown fuseAction:Check that all phases are present on the terminal block for incoming supply.If not, check the fuses in the ca

11VMIFB202Troubleshooting Guide Alarm motor protectionDefective or incorrectly set motor protectionAction:Use a hook-on ammeter to establish when the

12VMIFB202The circulation pump’s integrated alarm has deployedAction:Check if there is air in the heat transfer uid circuit that can gather in the ci

13VMIFB202Troubleshooting Guide Alarm BrinepumpThe circulation pump’s integrated alarm has deployedAction:Check if there is air in the brine circuit

14VMIFB202Alarm BrineAction:Check the set value on ALARM BRINE in the heat pump’s control computer under service-heat pump-temperatures-alarm brine.

15VMIFB202Alarm sensorAction:Measure the resistance of the sensor, check the ohm value against the temperature according to the table below.. If the a

16VMIFB202Alarm communicationAction:Check if the communication between the display card and relay card is broken.Test with another TP cable or communi

17VMIFB202Phase dropAction:Check that there is 230 V between incoming L2 on the circuit board and neutral on block 220. Check if the overheating prote

18VMIFB202Whistling expansion valveAction:Try tapping gently on the expansion valve.Open and close the valve fully in and out and adjust the expansion

19VMIFB202The compressor’s IPR valve opensAction:When the valve opens, this is indicated by the pressure on the low pressure side rising and reaching

2VMIFB202The incoming phases have the incorrect sequence (only applies to 3-phase heat pumps).Action:Reset the phasesWhen the compressor runs with the

20VMIFB202Touching pipes – vibrationsAction:Establish which pipe(s) causes vibrations and try to remove the tension that is causing the vibrations by,

21VMIFB202Vibrating protective sleeves on the pressure switchesAction:Establish where the vibration noise occurs, if the vibration is in the protectiv

22VMIFB202Defective 3-way valve motorAction:Check that the motor can be run to the limit positions in a manual test.If it is still, measure at the mol

23VMIFB202Water heater too small in relation to requirementAction:Check the requirement and the water heater capacity.Replace with a larger heater or

24VMIFB202The house heating comfort is not adjusted to the customer’s requirementsAction:Check the ROOM, CURVE and MIN settings. Adjust incorrect valu

25VMIFB202Defective Honeywell 3-way valveAction:The motor should set the valve to the relevant end position depending on operating conditions. If it d

26VMIFB202Defective G2 shunt (HGW)Action:Check the function of the HGW shunt by test running it manually. If the motor does not shift mode during manu

27VMIFB202Basic setting G2 shunt + motorAction:Important to reset the shunt after taking the shunt apart!The groove of the white six edged sleeve must

28VMIFB202Only runs on the additional heatAction:Ensure that the heat pump is not in additional heater only mode. If additional heater only mode is se

29VMIFB202Incorrect ow in the brine circuitAction:Check the dierence between the supply and return line using a digital thermometer. The dierence s

3VMIFB202Troubleshooting Guide Working pressostat and high pressure pipeThe operating pressure switch does not closeSwitch o the main switch for the

30VMIFB202Build-up of ice under and around the outdoor unit or water collectingAction:Drain the ground under and around the outdoor unit so that it ca

31VMIFB202Outdoor sensor/Defrost sensorAction:Check that the outdoor sensor/defrost sensor is installed according to the installation instructions and

32VMIFB202Room sensorThe image shows one of the models of room sensor availableThe room temperature sensor has a temperature sensor that provides a fu

33VMIFB202Water does not get hotAction:Check fuse(s).Check if there is cold water supply, if not, check why and rectify the fault.Check if the overhea

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its

4VMIFB202Hot gas temperature too high See in service under heat pump also check using own digital thermometer.Action:Check the refrigerant circuit see

5VMIFB202Troubleshooting Guide Alarm high pressureBlocked strainer in the heating system return Action:

6VMIFB202Tip!Be careful not to spill water because there are electronics under the radiator pump; use something to protect the electronics.NOTE! This

7VMIFB202Troubleshooting Guide Alarm high pressureThe operating pressure switch does not open but the heat pump opens at high pressure Action:Check t

8VMIFB202Blocked strainer on the brine circuit.Action:Check for brine in strainer (if necessary clean the strainer)Closed taps, main tap or ller cock

9VMIFB202Troubleshooting Guide Alarm low pressureExpansion valve defective or incorrectly setAction:Check that the cooling is correct for the specic