BENSON HEATING LTD GUH100, User Instruction

Page: 28 / 41

GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 28 of 41
5.0 Fault Diagnosis
Fig 19
Fig 20
Fig 21
Pilot
Burner fails
to light
No Spark
Air in Gas
Supply
Check HT leads &
Connectors Check
Spark Ignitor
Pilot Feed
Restriction
Purge Gas Line to
Remove Air
No Gas
Supply
Check Pilot
Adjuster is Fully
Open and that the
Pilot Tubes are not
blocked
Check Gas Supply
is Present and that
Gas Taps are open
Pilot
Burner
lights and
becomes
established
but the
Main
Burner fails
to light
Pilot
Burner
Lights but
flame does
not become
established
Pilot Flame not
being sensed by
Thermocouple
Check that the Pilot
Flame Path is
supplying Heat to the
Thermocouple
Pilot Flame is too
small
Check that the
Thermocouple is
Connected to the Gas
Valve Correctly
Check that the Pilot
Flame Adjuster is
correctly set and that
the pilot feed is
Unrestricted
Reposition
Thermocouple
and / or Pilot
Flame Shroud
Replace Faulty
Thermocouple
Check that all
External
Controls are set
to Demand Heat
Check that
there is Power
to the Heater
Check Limit
Stat Reset
Check Fuse
Check
Thermostat
Check Time
Switch
Check that the
Gas Valve is not
Open Circuit
Replace
Gas Valve