Combi V3, Combi Max and Vortex Combi models
56
13 - FAULT FINDING
Vortex Combi only - Central heating OK - poor or no domestic hot water
13.5
No water flowing fr
om hot tap
No hot water operation
F
AUL
T
Hot water f
or short period only
Low water temperatur
e at tap
Mains water supply is not connected to cold water inlet of boiler
.
One or more isolating valves, stop cocks, etc. in the pipework are closed.
The cold water isolating valve in the boiler is closed.
There is a blockage (or blockages) in the pipework.
Store switch is set to OFF
.
Insuf
ficient flow of water through boiler
.
Hot tap is not connected to hot water outlet of boiler
.
Boiler cold water and hot water connections reversed.
Flow switch is not operating.
Primary store is not up to temperature.
Primary store (hot water) pump is not operating.
Faulty Hot W
ater PCB sensor
.
Faulty Hot W
ater PCB.
Relay No.1 faulty - not switching.
Flow of water through boiler too high.
Thermostatic mixing valve incorrectly set.
Primary store (hot water) pump speed too low
.
Faulty Hot W
ater PCB sensor
.
Faulty Hot W
ater PCB.
Burner not firing for hot water (after a short time).
Note: Burner will not necessarily fire as soon as tap is opened.
Burner oil pressure set too low on oil pump.
Incorrect nozzle fitted to burner
.
POSSIBLE CAUSE
Check and rectify as necessary
.
Open all valves in pipework to and from boiler
.
Open valve fully (located in the top right of boiler).
Check and rectify as necessary
.
Check store switch is set to ON (on boiler control panel).
Check flow is at least 3 litres/min - rectify as necessary
.
Check and rectify as necessary
.
Check and rectify as necessary
.
Check flow switch is correctly fitted - in line with flow
.
Check continuity across flow switch between terminals 10 and 1
1.
Set store switch to ON - burner and hot water pump should start.
Check for 230 V supply to pump with water on.
Replace sensor and check operation.
Check for 230 V output from 'Burner' terminal on PCB.
If no output - replace Hot W
ater PCB and check operation.
Check for 230 V to 'Flow switch' terminal of Heating PCB.
Reduce flow and check water temperature.
Set mixing valve to setting '4.5'.
Check pump speed is set to maximum - setting 3.
Replace sensor and check operation.
Check for 230 V output from 'Burner' terminal on PCB.
If no output - replace Hot W
ater PCB and check operation.
Check operation of boiler on heating - set switch to 'Constant'.
If burner faulty
, refer to burner fault finding chart.
Check and set oil pressure to correct value (see Section 4.3, 4.4, 4.6).
Check and fit correct nozzle (see Section 4.3, 4.4, 4.6).
ACTION