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SERVICING
FAULT FINDING
The PulsaCoil Stainless appliance control panel and printed circuit control board/
display have been designed to be fully automatic whilst able to provide functional
and diagnostic information to the householder/installer.
The panel/board work in conjunction with a number of sensors (thermistors) located
as shown in the diagram below.
Automatic Control Operation
The hot water temperature is controlled by sensors S3 and S4.
S3 checks for a drop in temperature every second and if the drop is more than 2ºC,
it switches on the hot water pump to raise the domestic hot water temperature to
52ºC (± 2°C).
The control of the hot water temperature is carried out by sensor S4 adjusting the
speed of the hot water pump.
The pump is stopped once S3 reaches a temperature of above 30°C.
The following checks should be carried out by the installer before calling the manufacturer.
Noise When Hot Water Tap Is Opened/closed
If the plate heat exchanger pump is noisy when the hot water tap is opened, then
check the level of water in the F & E cistern and vent the pump if necessary.
Water hammer - loose pipework and/or tap washers and/or washing machine valves.
Causes of ‘Unsatisfactory Hot Water Service’
See table opposite.
Overflow from Feed and Expansion Cistern
Check
that the controlled level of water in the cistern is at the correct level. Adjust if
required and check the ballvalve is shutting off the water supply.
S6
On/P Heater
Off/P Heater
S4
S3
Sensors
S3 DHW inlet sensor
S4 DHW outlet sensor
S6 Store sensor
Fault
Condition
Possible Causes
DHW
temperature
remains cold
exiting the
taps.
- Thermal store is cold/DHW
pump is permanently stuck
- Temperature sensor or printed
circuit control board is faulty.
- The water level is low in the F&E
Cistern
- Overheat immersion stat tripped
- One or both immersion heaters
have failed
DHW
temperature
fluctuates
wildly when
flow is steady
- DHW pump keeps sticking
intermittently
- Hot & cold crossed at appliance.
DHW
temperature
exceeds and
remains well
above 60°C
when the
flow rate is
low.
- DHW printed circuit control
board and/or temperature
sensor is/are faulty.
- Immersion heater thermostat
temperature setting too high
should be 70°C.
Store not
heating
- The two switches on the
isolating terminal connectors
are not pushed home - i.e. unit is
not commissioned.
- No power supplies/fuses are
blown.
- Overheat immersion stat
tripped.
- One or both immersion heaters
have failed.
Summary of Contents for PulsaCoil PCS 120
Page 25: ...Page 25 APPENDIX APPENDIX B ...
Page 27: ...Page 27 NOTES NOTES ...
