Fault Finding - Kensa Group Kensa Heat Pumps P250X 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
Plant Room Heat Pump Manual Version 11.1
Page 30 of 34

6. Fault Finding

Possible Cause
No power supply
Controls MCB tripped
There is no call from the BMS 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.
Low gas pressure in machine. Can occur
simultaneously with an A1 alarm.
Filters maybe blocked
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 or blocked filters.
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 wall mounted electrical isolator switch
or call electrician
Call electrician to investigate cause
Programme BMS according to manufactur-
er's instructions
No fault
Check the pressure gauges below the two
water pumps. The pressures should be be-
tween 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
make up system needs to be operated.
Bleed the heating distribution system pump
within the heat pump, using the schrader
valve above the pump. (See Fig 19).
Check that the water pumps are operational .
Check that the water pumps are operational
and no filters are blocked
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. Do not run the
compressor until the unit has been defrost-
ed.
Check antifreeze has been added and unit
commissioned correctly.
Check that the water pumps are operational
Ensure no flow restrictions and wait approxi-
mately 4 hours (with the machine turned off)
for automatic reset.
Refer to Kensa Technical department