Is the Boiler and CH System filled with water and all
isolation, system filter and radiator valves open?
YES
Fill and vent the system and open all
isolation valves, then restart boiler
Is the Flow/Return Differential across the Boiler in
excess of 30°C?
NO
Check that the Pump is rotating freely.
Is the Differential now below 20°C?
YES
NO
Replace the Pump,
then restart boiler
NO
OK, now restart boiler
YES
Check the Flow and Return Thermistors
Check resistance using a suitable multimeter
connected across the thermistor’s terminal pins
Temperature
Resistance kΩ
25
o
C
9.7 – 10.3
60
o
C
2.4 – 2.6
85
o
C
1.0 – 1.1
[Keston] Technical Help Line:
[01482 443005]
[Spares: 01482 498665]
Exit
Next
Fault Help
Only carry out the following
tests if you are gas safe
qualified
Exit
Next
Fault Help
Press
Low Water Pressure
Ignition Lockout
Overheat Lockout
Exit
Down
Up
Enter
Fault Help
Press
Press
Exit
Down
Up
Enter
Menu
Change Service Time
Fault History
Fault Help
Vent System
Sensor Readings
Press
Fault finding help can be accessed through the menu. Fault
finding help lists all the common faults with the necessary
checks. More detailed fault checks and actions are described in
the following pages.
4.2 OVERHEAT LOCKOUT
56
Installation and Servicing
Section 4 - Fault Finding
Section 4 - Fault Finding
FAUL
T FINDING
Refer to Section
3.14
&
3.29
4.1 MAIN MENU, FAULT HELP
