25
NOTE: Rectification of any internal burner component must be done by a qualified burner engineer.
Symptom
A. Burner will not start
B. Burner starts i.e. burner
motor runs but will not
light and burner control
box goes to 'lockout'.
C. Burner motor starts but
stops and re-cycles.
D. Bur ner shuts down
during operation and
recycles.
E. Bur ner shuts down
during operation and
goes to 'lockout'.
Possible Cause
1. Electrical supply failure.
2. Air pressure switch on burner not
operating.
3. Control thermostat, time, water
pressure switches or other boiler
system controls at fault.
1. No ignition spark.
2. Gas starvation.
3. Ultra-violet cell fault.
1. Air pressure switch on the burner.
As C1 above.
1. Flame failure
2. Ultra-violet cell fault.
Action
1. Check:
a) Main isolator switch is on and
power is available at the
control panel.
b) Overload protective devices
of burner motors (if fitted).
2. Switch contacts must be in the
burner start position. Check
switch is not stuck in the satisfied
position.
3. Check:
a) That all switches are closed
b) Booster is not locked out due
to low inlet gas pressure and
that pressure switches
function correctly.
4. Reset and check. Also check
control thermostat setting and
operation.
1. See action B1. (Page 27)
2. Purge gas pipe, check pilot valve
operation.
3. Remove, clean and check
connections and replace if
necessary.
1. Check:
a) burner damper is open to
usual extent.
b) air inlet to switch is not
blocked.
c) switch is not stuck.
d) electrical connection.
As C1 above.
1. Check gas supply and pressure.
2. As B3 above.
Gas Burner Fault Finding Chart
Gas Burner Fault Finding Chart
August 2014
