55
Combi V3, Combi Max and Vortex Combi models
13 - FAULT FINDING
No operation on heating
Timeswitch either not set, or not in an 'ON' period.
Timeswitch not operating.
Faulty timeswitch.
Faulty timeswitch switch contacts.
Timeswitch OK but not switching boiler on.
Heating switch set to 'HOT WATER ONLY'.
Room thermostat not calling for heat.
Faulty room thermostat.
No room thermostat or external timeswitch connected to boiler.
Boiler thermostat is set too low.
Boiler thermostat faulty.
Boiler is underfired.
Combustion setting of burner incorrect.
Boiler heat exchanger is sooted up.
Check setting and set to 'Constant' to test.
Check power supply to timeswitch.
Check and replace if necessary.
Check continuity of switch, replace if necessary.
Check continuity of wiring to timeswitch.
Check and set switch to 'Constant' to test.
Set thermostat to call and check boiler operates.
Check continuity of thermostat, replace if necessary.
Check link fitted between 8 & 9 on boiler terminal block.
Check and reset as necessary.
Check and replace if necessary.
Check nozzle size & fuel pressure, correct as necessary.
Check settings and correct as necessary.
Check boiler & baffles and clean as necessary.
FAULT
POSSIBLE CAUSE
ACTION
Flow temperature low
Combi V3 and Combi Max only - Domestic hot water OK - poor or no central heating
13.4