WD51/2/1997 Chapter 5 : Fault Finding
The Keston 170 Condensing Boiler
Installation & Servicing Instructions
Page : 27
From sheet 3
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Continued on sheet 3
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Continued from sheet 1
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Does ignition sequence start?
Is lockout light on?
Has the Air Press. Switc h
changed over?
Are tubes and connections to
the Air Press. Switch sound?
Is the ai r press. across the A ir
Press. Switch more than 4 in
water?
Is the air filter dirty or the air
inlet, exhaust or condensate
pi pe blocked?
Is the B urner blocked
Fan faulty - change
Is the gas fl ow rate to the boil er correct
for the gas type in use (ie LPG or Nat.
Gas )?
Is gas supply pressure at gas
valve correct?
Is gas burner pres sure per
specification (Secti on 4.7)?
Is gas valve opening?
Check gas supply or turn on
gas cock.
Replace gas ori fice.
Faulty gas val ve - replace.
Switc h off & if problem persi sts
replace control box.
Blocked air fil ter - replace
OR
Faulty control box - replace
Correct tube connection
Faulty pressure switch -
replace
Replace air filter
OR
clear bl ockage
Clear bl ockage
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