Keston K170 Installation And Servicing Instructions page 30

WD51/2/1997 Chapter 5 : Fault Finding
Continued from sheet 1
yes
Is the gas flow rate to the boiler correct
yes
Continued on sheet 3
Installation & Servicing Instructions
Does ignition sequence start?
no
Is lockout light on?
yes
Has the Air Press. Switc h
changed over?
no
Are tubes and connections to
the Air Press. Switch sound?
yes
Is the air press. across the Air
Press. Switch more than 4 in
water?
no
Is the air filter dirty or the air
inlet, exhaust or condensate
pipe blocked?
no
Is the Burner blocked
no
Fan faulty - change
for the gas type in use (ie LPG or Nat.
Gas )?
no
Is gas supply pressure at gas
valve correct?
yes
Is gas burner pres sure per
specification (Section 4.7)?
no
Is gas valve opening?
yes
The Keston 170 Condensing Boiler
no
Switc h off & if problem persists
replace control box.
yes Blocked air filter - replace
Faulty control box - replace
no
Correct tube connection
yes
Faulty pressure switch -
replace
yes
Replace air filter
clear blockage
yes
Clear blockage
no
Check gas supply or turn on
gas cock.
yes
Replace gas orifice.
no
Faulty gas valve - replace.
OR
OR
From sheet 3
Page : 27