Fault Finding - gledhill BOILERMATE CP BMSCP120 Instruction Manual

SERVICING AND MAINTENANCE
Test Equipment
The initial assumption in this procedure is that the plumbing and water supply is
working effectively. If in doubt please confirm and refer to the end of this section for
advice on specific components.
A multi meter, a weir gauge and a thermometer will be required to confirm that all
the components are working effectively.
The PWM controller PCB manufacturer suggests "Fluke 87 TRUE RMS Multi meter" as
a suitable product. This will be able to measure;
- the frequency output form the Board to the pump
- the Duty cycle % output from the Board to the pump
Connection numbering
For reference the connections to the PCB are numbered below for
1
4 5 6
2 4
J19
1 3
2 4
J20
1 3
7
14
6 13
5 12
4 11
J18
10
3
2 9
8
1
J7
J3
2
8 7 6 5
4 2 1
3 1
Logical sequence;
- check electrical connections fault finding section on page 23 first to ensure your
own safety. This section will potentially identify any short circuited components
and/or wiring faults that need to be rectified before continuing to work on the
appliance.
- check that the correct information is being supplied to the board. This section will
identify if any sensors are faulty or out of tolerance. These will need to be replaced
before continuing
- check that the overheat link is present
- check that the outputs to the board are being generated. If at this stage the board
does not provide the correct outputs then potentially the board should be replaced
- check the pump electrical circuit

FAULT FINDING

2 3
J1
J8
6 1
7 2
8
3
9
4
10 5
Page 24
SERVICING AND MAINTENANCE
Electrical power connections
Reference schematic Check procedure
opposite
Power supply to PWM Electrically isolate power supply at fused spur switch and remove fuse.
Controller PCB
Earth continuity test (dead test) – to ensure that the appliance is earthed
Mains voltage test (dead test) - to ensure that the appliance is isolated
Resistance to earth (dead test) – to ensure that the wiring insulation to the product is intact
Short circuit test (dead test) – to ensure that no components in the products circuit have a short circuit
Visually inspect wiring is correct as per fig 4.3
Connect supply
Polarity test (live test) - to ensure that the live is connecter to the live etc
• Check 230V ac across L1 to Earth
• Check 230V ac across L1 to N
• Check for 0 to 15V ac N to earth
Reference to "Boilerfault finder.com" gives clear instructions to on how to perform these tests. (Menu
options 1st. Boiler Fault finder 2nd. Electrical safety checks).
Check inputs to the PWM Controller PCB
Reference schematic Check procedure
opposite
CW temperature sensor Power off
Disconnect J18
Measure and record the resistance across terminals 6 and 13
Measure the cold water inlet temperature
Compare the resistance measured with chart "Tasseron NTC 12k thermistor"
The reading should make sense taking measurement conditions into consideration
TS temperature sensor Power off
Disconnect J18
Measure and record the resistance across terminals 3 and 10
Measure the thermal store temperature
Compare the resistance measured with chart "Tasseron NTC 12k thermistor"
The reading should make sense taking measurement conditions into consideration
HW temperature sensor Power off
Disconnect J18
Measure and record the resistance across terminals 7 and 14
Measure the Hot water temperature
Compare the resistance measured with chart "HUBA combined flow sensor and NTC 10k thermistor"
The reading should make sense taking measurement conditions into consideration
Flow sensor Power on Sensor required a power supply 5 VDC
Open a HW tap and set to a flow rate.
Measure and record the frequency across terminals 1 and 12
Compare the frequency measured with chart "flow rate determination"
The reading should make sense taking measurement conditions into consideration
FAULT FINDING
Page 25