FIND FAULT
POSSIBLE CAUSES SOLUTION
Comb’ chamber Glows
Red.
Low process airflow.
Reset air.
Main flame too long.
Check the adjustment of the gas
control valve.
Combustion air set too low.
Check air dampers, linkages and
air filter (where fitted).
Unit will not achieve
temperature.
Too much process air.
Check and reset air.
Burner input setting too low. Check and reset Burner.
Leakage of cold air into
system.
Source and rectify.
Burner shuts down (see
also sheets M8.1 to
M8.4b).
Control circuit operating.
Check control circuit, process
airflow switch, over temperature
limits and low fire settings.
Flame sensor not detecting
the flame.
Check flame sensor installation
and position.
Too much pressure in
chamber.
Check Flue.
Unit Produces
condensation.
Burner turned down too
low.
Check the adjustment of the gas
control valve.
Low process air volume.
Check and reset air.
Fault Finding Guide (Indirect Heaters)
Page 15
Comtherm Ltd
Installation & Maintenance Manual
Burners, Heaters & Combustions Systems