Supplied By www.heating spares.co Tel. 0161 620 6677
59
FAULT FINDING
Sheet B
Check operation of pump and fan
Tur
n off the main ON/OFF control to the
"0" position
Diconnect the power supply to the boiler
Go to sheet A
Check transfor
mer 230 V
AC primar
y
(black/red) and approx. 17 VDC secondar
y
(blue/brown)
Check/replace pump
Replace fuse F1
If fan commences operation, exchange
gas valve
After approx. 20 secs.
Does fuse F1 blow?
Produce central heating demand.
Does fuse blow immediately?
Tur
n the main ON/OFF control to the "1"
position
Does green power on indicator glow?
Ye
s
No
No
No
Ye
s
Check/replace fan
Replace electronic board
No
Ye
s
Ye
s
Does green power on indicator glow?