Keston K170 Installation And Servicing Instructions page 29

WD51/2/1997 Chapter 5 : Fault FindingThe Keston 170 Condensing Boiler
5.2 FAULT FINDING FLOW CHART
START
Is amber switch light on?
yes
Is there 230V between
terminals SL & N?
Is the boiler switched on?
Faulty Switch Neon
-Replace.
Is the f an running?
yes
Is the boiler thermostat closed?
Is there 230V between control
box pins 10 & 2 and between
pins 10 and 1?
Is the air pressure switch stuck
in the NO position?
Is there 230V between control
box pins 6 & neutral?
Is the motor relay operating?
Is there continuity between live
supply from relay to blower &
Neutral through motor
resistance?
Is motor overload tripped?
Is there wiring continuity
& in-line connector
to motor?
Continued on sheet 2
Installation & Servicing Instructions
no
no
yes
no
yes
no
no
yes
no
yes
yes
no
no
yes
no
yes
yes
no
yes
no
no
Apply Power To Boiler.
Check External Controls.
Switch On Boiler.
Boiler return is too hot. Allow
to cool. OR faulty thermostat -
Replce.
Check continuity (see section
5.3)
Faulty pipe connections to Air
Press. Switch. OR Faulty Air
Press. Switch - Replace.
Control box faulty.
Relay not secure in socket or
relay faulty - replace
Motor/Fan fault y - Replace.
Wait for motor to cool.
Identify & correct break.
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