Fault Finding - Kensa Heat Pumps Shoebox Heat Pump User Manual

Many faults which occur on commissioning are found to be due to incorrect wiring or setting up, therefore
it is recommended that a thorough check is carried out should there be a problem.
Symptom
Blank display on software controller
Compressor not running but display
reading temperature near setpoint
Display flashes fault code tP
Display flashes fault code HP
Display flashes fault code LP
Display flashes fault code A1
Display flashes fault code E1, E2, E3 or E4
Shoebox Heat Pump Operational Manual Version 2.1
Page 14 of 20

5. Fault Finding

Possible Cause
No power supply
Controls MCB tripped
There is no call from the time-clock or
thermostat for heat pump operation
Heat pump is up to temperature
Low water pressure in the ground or heating
system side due to pipe relaxation or other
pressure loss.
Overheat warning. No or low flow around
heating distribution circuit because of air in
water pump, or stuck water pump impellor,
or heating distribution system valves/
actuators closed.
HP can also be temporarily displayed when
the heat pump reverts from DHW to space
heating mode.
Low gas pressure in machine. Can occur
simultaneously with an A1 alarm.
Can occur temporarily on first start up when
unit is new or after a long period out of use.
Insufficient antifreeze added and heat pump
frozen.
Freeze protection system activated. Low or
no water flow on the ground (cold) side of
the machine. Can also occur after many
months of running in very cold weather.
Loss of contact with probes inside heat
pump. E4 could be loss of contact with
weather compensation sensor
Action
Check Fuse in plug and replace if necessary.
Check wall mounted electrical isolator switch
or call electrician
Call electrician to investigate cause
Programme time-clock according to manu-
facturer's instructions
No fault
The pressures should be between 1 and 2
bar. If below this, the pressure needs to be
increased above 1.8 bar
To increase the pressure in either circuit, the
cold fill valve will need to be opened.
Check that the water pumps are operational
and spin the impellors. ( See section 6.3 )
No action
Check that the water pump is operational
and spin the impellors (see section 6.3)
If symptom persists outside of the two listed
circumstances, contact Kensa Technical de-
partment.
No action
Allow heat pump to defrost and add the
correct antifreeze quantity.
Check antifreeze has been added and unit
commissioned correctly.
Check that the water pump is operational
and spin the impellors (see section 6.3)
Ensure no flow restrictions and wait approxi-
mately 4 hours (with the machine turned off)
for automatic reset.
Refer to Kensa Technical department