38
Faulty ignition
Check that the gas type is
suitable for heater
Check gas pressure
Check head pressure.
Check gas supply pipes have
been purged of air.
Heat exchanger dirty
Check heat exchanger
Burner shuts down
No indication lights on
Pressure differential switch not
operating
Check air intake pipes are not
blocked .
Check flue pipes are not
blocked check operation of flue
venter
Faulty differential pressure
switch
Replace differential pressure
switch
Room thermostat in hot air flow
Check position of thermostat
The burner goes out due to
the intervention of the
thermostat SND; and is
restarted automatically when
heater has cooled down
Yellow light on.
Excessive heat exchanger
temperature
Check that the gas type is
suitable for heater
Check gas pressure
Check head pressure.
Check injector size is correct for
the heater
Excessive air temperature due
to poor air flow.
Check that the fan blades are
clean.
Check that the horizontal and
(vertical if fitted) louvres are
sufficiently open (see
installation).
Check fan is operating correctly
with sufficient air flow.
Faulty SND thermostat or faulty
fan control l
Change SND thermostat or fan
control l
The burner goes out due to
the intervention of the
thermostat TR. and is
restarted automatically when
heater has cooled down
Yellow light on.
Excessive heat exchanger
temperature
Check that the gas type is
suitable for heater
Check gas pressure
Check head pressure.
Check injector size is correct for
the heater
Excessive air temperature due
to poor air flow.
Check that the fan blades are
clean.
Check that the horizontal and
(vertical if fitted) louvres are
sufficiently open (see
installation).
Check fan is operating correctly
with sufficient air flow
Faulty thermostat
Change thermostat
Burner goes out due to the
intervention of the LIMIT
thermostat (LM).
Yellow light flashing
Excessive heat exchanger
temperature
Check that the gas type is
suitable for heater
Check gas pressure
Check head pressure.
Check injector size is correct for
the heater
Excessive air temperature due
to poor air flow.
Check that the fan blades are
clean.
