Lennox FCM 85 Installation, Operating And Maintenance page 58

HEATING : GAS BURNER
GAS BURNER TROUBLESHOUTING
If faults reported on CLIMATIC
-Reset the CLIMATIC.
-Check voltage: 230V after circuit breaker.
-Check GAS isolation shut-off valves are open.
-Check GAS pressure at the inlet of the GAS valves. It must be >20 mbar when the Burners shut down.
-Adjust the set points to priorities the burner. Increase the value of the room temperature set point to a temperature higher than
actual room temperature.
DIAGNOSTIC TABLE BALTIC GAS BURNER
NORMAL
STAGE
OPERATION
Heating Extraction fans
Requested start
Starting of
the Extraction Fans
extraction are running
fans
After 30 to 45
seconds: pre-
Extraction ventilation the
Fan is ON fire-up
electrode
should spark.
Continuous
After a few
ventilation
seconds the
and sparks
gas burner
from fire up
fires-up
electrode.
FLEXYII-IOM-0409-E
POSSIBLE
FAULT
Fault on the
+ Check connections on the blower
blower
thermostat.
thermostat
Lack of gas
+ Check valve's opening & supply pressure
supply
Fault on the
superheat
+ Check superheat thermostat's operation
thermostat on the
after manual reset
gas burner
support bar
After 10 seconds
safety shutdown + Check connections of the control block on
by the ignition the gas valve
control block
+ Check the free movement of the fan wheel
+ Check Electrical connection on the Gas
Nothing happens Ignition Control Block and on EF connection
Board
+ Check the Fan supply voltage
+ Check the fire-up electrode
Continuous
+ Check the pressure drop at the pressure
Ventilation
switch: It must be higher than 165 Pa
without sparks
+Check the good operation of the pressure
from fire-up
switch using an Ohmmeter and by artificially
electrode
creating a depression in the tube.
After 4 seconds
the GAS Burner
+ Check injection pressure during start-up
still not operating
(Value for High Heat)
and safety
+Remove the control box from the gas
shutdown by the
block.
Ignition Control
Block.
Within 4 seconds + Check the Position and connection of the
the gas Burner Ionisation Probe. It must not be Earthed
fires-up BUT (230V).
safety shutdown + Measure the Ionisation Current: It must be
from the Ignition higher than 1.5 microAmps.
Control Block. + Check the Type of GAS.
ACTION POSSIBLE SOLUTION
+ Replace thermostat
+ Restore gas supply
+ Replace superheat
thermostat
+ Repositioning of the
control block on the valve
+ Replace valve
+ Replace fan
+ Replace EF connection
board If necessary
+ Re-position the pressure
switch tube.
+ Change the pressure
switch.
+ Remove the air from the
Gas pipe-work
+ Adjust the injection
pressure to high heat
value.
+ Change the Control Box
if the Gas valve is OK.
+Check the whole
electrical supply.
+ Adjust the supply and
injection pressure if gas is
different from natural gas
G20 :( G25 Gas of
Groningue for example).
Page 57