Worcester 24i RSF Installation And Servicing Instructions page 32

L
Air Pressure Switch Check
Remove BROWN and
WHITE terminals
from air pressure
switch
With no demand, is a
short-circuit observed
at exposed APS
terminals?
YES
Reconnect the
WHITE & BROWN
wire and remove the
GREEN wire. Initiate
a demand.
Does the fan run?
YES
With fan running
disconnect BROWN
wire. (DO NOT touch
chassis with it). Is a
short circuit observed
across exposed APS
terminals?
YES
APS OK
Gas Valve Check
Is gas pressure present
at input to gas valve?
YES
Is live output present at
X5 pins 1 & 2 relative to
neutral at pin 3?
YES
Is gas pressure present
at input to burner?
YES
Gas valve OK
Supplied By www.heating spares.co Tel. 0161 620 6677
NO
Air pressure switch
faulty
NO
Is there mains 230V
at fan connector X4
pins 1 and 3?
YES
Fan or fan cable
faulty
NO
Air pressure switch
faulty
NO
Ensure gas supply
NO
Faulty board
Replace
NO
Faulty gas valve
Replace
32
NO
PCB faulty