MODENA 80 E
33
In order, the five lights indicate:
1 Boiler On Indicate
2 Boiler Shut down warning
3 Domestic Hot Water circuit ON
4 Central Heating standby (Flashing Light)
Central Heating circuit ON (Permanent Light)
5 Insufficient pressure in Central Heating System (Flashing Light)
Electric power supply ON (Permanent Light)
Note: Always check for sufficient gas supply (20mbar inlet working pressure for NG and 37mbar for LPG). Minimum
of 22 mm diameter pipework on C.H. flow and return with adequate by-pass. A correctly installed flue system and
a 3 amp fuse.
8.03 MF03 PCB
When operating the C.H. the following lights should be on: 4, 5 and flame on light. For D.H.W. the following lights
should be on: 3, 5 and flame on light.
If the boiler works for C.H. but not D.H.W., or vice versa, a number of components must be functioning and can,
therefore, be eliminated as being at fault.
Boiler will not light for D.H.W.
If boiler works for C.H. but not for D.H.W. the fault is most likely to be the flow meter or D.H.W. sensor.
If the tap symbol light is on the fault is the D.H.W. sensor. If this light is not on then suspect the flow meter has not
operated.
Boiler will not light for C.H.
If the boiler works for D.H.W. but not for heating the fault is most likely to be external controls (i.e. clocks or room
thermostats). Integral clock if fitted or C.H. sensor.
If the heating demand light is on the fault is most likely the C.H. sensor. If this light is not on suspect either a clock
or room thermostat not calling.
To override/eliminate any external controls disconnect them from terminal 3 and 4 underneath the boiler and refit
the link wire (see fig. 20).
Boiler will not light for D.H.W. or C.H.
The fault is likely to be a component common to both services. Open a hot tap to create a demand - is there a spark
at the ignition electrode?
Yes Suspect gas supply, pressure or gas valve.
No Is fan running?
Yes Suspect air pressure switch or overheat stat (if boiler locks out without sparking go to overheat stat)
No Is low water pressure light Flashing?
Yes Top up water to above 1 bar. Does the light go out? (if water pressure o/k suspect high limit stat)
Yes Does fan start?
Yes Does boiler light?
Yes Is hot water OK?
Try heating, if heating does not work follow guide for heating faults. Does low water pressure light
go out?
No Suspect low water pressure switch.
If boiler still does not fire see comprehensive fault finding chart.
