FAULT FINDING (cont…)
Fault
Possible Cause
Remedy
6.
Pilot alight, no main flame, burner goes to lockout
a)
Main valves not opening
a)
Check main valves
7.
Main flame goes out after lighting
a)
Low gas pressure switch (if fitted) set too high
a)
Reset pressure switch
b)
High gas pressure switch (if fitted) set too low
b)
Reset pressure switch
c)
Pilot too high
c)
Re-adjust pilot
d)
Flame not detected
d)
Adjust flame detector to see main flame
8.
Main flame goes out on reaching high fire
See “Main flame goes out after lighting”
See “Main flame goes out after lighting”
9.
Flame goes out. No lockout.
a)
High or low gas pressure switch (if fitted) faulty
a)
Rectify switch
b)
Duct pressure switch faulty
b)
Rectify switch.
c)
Loss of duct air pressure
c)
Check main duct fan
d)
Interlock operated
d)
Re-make interlock
10. Flame goes out. Burner goes to lockout.
a)
Loss of gas
a)
Turn off gas and investigate
b)
Loss of combustion air
b)
Check combustion air fan
c)
Failure of flame detector
c)
Change detector
11. Burner goes to lockout when it is turned off
a)
Main gas valves not shutting completely
a)
Check main valves at once. Turn gas off at
ball valves.
12. Heat output not maintained
a)
Gas pressure failing
a)
Investigate
b)
Burner faces need cleaning
b)
Clean burner (see under ‘Maintenance’)
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