Keston 50 - GC Installation And Servicing Instructions page 31

WD50/2/1997
5.2 FAULT FINDING FLOW CHART
Is amber switch light on?
yes
Is there 230V between
Is the boiler switched on?
yes
Is the boiler thermostat closed?
Is there 230V between control
Is the air pressure switch stuck
Is there 230V between pins 6 &
Is there continuity between pin
6 & Neutral through motor
Is motor overload tripped?
Is there wiring continuity
Continued on sheet 2
Installation & Servicing Instructions
Chapter 5 : Fault Finding
STA RT
no
terminals L & N?
yes
yes
Faulty Switch Neon
-Replace.
Is the fan running?
no
yes
box pins 10 & 2?
yes
in the NO position?
no
neutral?
yes
resistance?
no
no
& in-line connector
to motor?
The Keston 50, 60 & 80 Condensing Boilers
Apply Power To B oiler.
no
Check External Controls.
no
Switch On B oiler.
no Boiler return is too hot. Allow
to cool. OR faulty thermostat -
Replce.
no
Check continuity (see section
5.3)
yes Faulty pipe connections to A ir
Press. Switch. OR Faulty Air
Press. Switch - Replace.
no
Control box faulty.
yes
Motor/Fan faulty - Replace.
yes
Wait for motor to cool.
no
Identify & correct break.
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