53
Installation and Servicing
Section 4 - Fault Finding
FAUL
T FINDING
continued.......
4.11 NO CH OPERATION
Is “Off” shown underneath the rad on the display?
NO
YES
Press Mode button (B) until “Off” not shown
Are CH Timer and Room Thermostat switched on?
YES
NO
Switch CH Timer and Room Thermostat On
Are the Radiator Valves Open?
YES
NO
Open the Radiator Valves
Is there 230Vac at SL1 IN?
YES
NO
No voltage from Timer/Room Stat.
This is not a boiler fault.
Ensure voltage is supplied to boiler by rectifying
external wiring.
Is an Outside Sensor connected?
YES
If an OpenTherm Room Stat is not connected,
is there a link wire across the OpenTherm
connections?
NO
Connect a link wire across the OpenTherm
connections.
L
N
YES
Ensure there is 230V at SL2 IN
NO
Check wiring from terminal strip to PCB
COMBI
HEA
T / SYSTEM
SL1
IN OUT
IN OUT
SL2
OPTIONAL
FROST STAT
ROOM
STAT/
TIMER L N
MAINS IN
UIN
230010 A01
L N
MAINS IN