BENSON AH150 - 6 Fault Diagnosis by Flow Charts

6.0 Fault Diagnosis
Fig 26
-
Burner fails
II
to run
-
~
Room
r---
Thermostat
Check Controls
Timer
~
Heat/Ventilate
No Demand
r---
Switch
On/Off Switch
~
No Power
Check Isolator
Check Fuses
Burner Lockout
Fan/Limit
Thermostat
Fig 27
-
Fuel Feed
Incorrect
I
Check that the
Oil Pressure is
Correct
I Check that the
. Head of Grav ity
is Sufficient
'--
Check that the
Suction Lift is
not
too great (two
pipe systems)
I---
Burner starts
ignition
sequence, but
fails to light
and lockout
occurs
-
-
Fuel! Air
Probl em
-
Check Burner Air
Setting/ Bleed
System
Air in System
Check that the
By-pass Plug is
Present
,I Possible Fuel
I Contamination
r----
-
~
Restricted Fuel
Feed
Check Valves/
Fuel Feed/ Filter/
Nozzle for
Blockages
and
Restrictions
-
~~ ~ -
\
No Spark Check Control
Check Efectrode
1---------1 1-------1
32