Burner goes out due to the
intervention of the SND
thermostat and is restarted
automatically when the heater
has cooled down .
Yellow indication light on.
Excessive heat exchanger
temperature
Check inlet gas pressure
Check burner head pressure
Check that gas type is suitable
for heater
Check injector size is correct for
the heater.
Excessive air temperature due
to insufficient air flow over heat
exchanger.
Check the fan blades are clean
Check that the horizontal and
(vertical if fitted) louvers are
sufficiently open. (see in
installation section of manual)
Check that the fan speed is
correct and the air flow over the
chamber is sufficient.
Faulty SND thermostat or
control panel
Replace SND thermostat or
control panel
Burner goes out due to the
intervention of the TR
thermostat and is restarted
automatically when the heater
has cooled down .
Yellow indication light on.
Excessive heat exchanger
temperature
Check inlet gas pressure
Check burner head pressure
Check that gas type is suitable
for heater
Check injector size is correct for
the heater.
Excessive air temperature due
to poor air flow
Check the fan blades are clean
Check that the horizontal and
(vertical if fitted) louvers are
sufficiently open. (see in
installation section of manual)
Check that the fan speed is
correct and the air flow over the
chamber is sufficient.
Faulty thermostat
Replace thermostat
