Installation manual
21 ©ESP Ltd. Sept 2008
6. Maintenance 6. Maintenance
If the heat pump is not to be run for a long time, please drain out all the
water in the unit and seal the unit to protect it. Please drain the water from
the lowest point of the heat exchanger to avoid freezing in winter when not
being used. Water recharge and full inspection of the heat pump is needed
before it is restarted.
Don't power off the unit when you use it regularly.
Check the air ducting for any obstruction and clear as required. The air
ducts MUST be totally cleared of any obstructions or it will adversely im-
pact upon the efficiency of the unit.
6.9 FAULT FINDINGS AND SOLUTIONS
6.9.1 The Heat Pump
Failure Display Indicator Cause Solutions
Power on Off
Unit running On
Lower tank water
temp. sensor failure
PP1 1 on 1 off The temp. sensor is open or short
circuit
Check and replace the temp. sensor for the
upper tank water
Upper tank water
temp. sensor failure
PP2 2 on 1 off The temp. sensor is open or short
circuit
Check and replace the temp. sensor for the
lower tank water
Evaporator coil
temp. sensor failure
PP3 3 on 1 off The temp. sensor is open or short
circuit
Check and replace the temp. sensor for the
evaporator inlet
Elec. Heater temp.
sensor failure
PP4 4 on 1 off The temp. sensor is open or short
circuit
Check and replace the temp. sensor for the
elec. heater
High pressure
protect
EE1 6 on 1 off 1. too much refrigerant
2. Bad air-side heat
exchange
1. Discharge the redundant gas (qualified
fitter required)
2. Clean the air-side heat exchanger
Low pressure pro-
tect
EE2 7 on 1 off 1. Insufficient refrigerant
2. Block on the filter or capillary
3. Inadequate water flow
4. Expansion sensor is broken
1. Check if there is any leaks and refill gas
2. Replace the filter or capillary
3. Clean the water side exchanger or dis-
charge the air in the water loop
4. Use new expansion valve
AUX heating
thermal protect
EE3 8 on 1 off Water level in tank too low Check the water supply or tank to see
whether there is adequate water
Exhaust temp.
protect
EE4 9 on 1 off 1. Shortage of refrigerant
2. Out of temp. setting too high
1. Check the gas pressure to see whether or
not it has enough refrigerant
2. Check the setting temp.
Communication
failure
EE8 On Communication failure between
wire controller and main board;
Check the wire connection between the
wire controller the main board
Defrosting Defrosting
indicate
Flash
Hot water air source heat pump Hot water air source heat pump