Technical data

49
Does fan run?
Does yellow fan operation indicator ( ) flash?
Does yellow flame indicator ( ) flash?
Does yellow fan operation indicator flash or glow?
Check air/flue gas system is correctly fitted and not obstructed. Check pitot tube (in fan outlet) and air hoses are not obstructed and are correctly aligned. Check or replace air pressure switch.
Check fan/flue gas system
Sheet E
Is 230 V present across fan terminals?
Does yellow central heating demand indicator ( ) glow? No heat demand. Go to sheet C.
Check/replace fan.
Yes
No
Yes
Yes
No
No No
No
Yes
Switch main on/off control off and on again.
Yes
Check NTC. Disconnect NTC lead at plug (3, fig. 37). Does fan run now?
Check connection to NTC temperature sensor, clean and tighten. Check NTC not shortened to earth. If O.K replace NTC sensor.
Replace electronic boards.
No
Yes
Does yellow flame indicator ( ) glow?
Defective electronic boards.
No
Does burner light?
Yes
Go to sheet F.
No
Go to sheet H.
Yes
Yes
Does yellow flame indicator ( ) flash?
No
Check pitot tube (in fan outlet) and air hoses are not obstructed and correctly aligned. Check or replace air pressure switch.
Yes
Does fan run now?
No
Yes
No