Lennox BCK 020 Installation Operating & Maintenance Manual page 51

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.
Table 6
STAGE NORMAL
Heating Contactors
Requested engaged
Contactors Extraction Fans
are are
engaged running
After 30 to 45
Extraction seconds :
fan is pre-ventilation the
ON fire-up electrode
should spark
Continuous After a few
ventilation seconds the
and sparks gas burner
from fire up fires-up
electrode
Page 50 - IOM / ROOFTOP BALTIC Series - 0803 - E
POSSIBLE
OPERATION
Contactors do + Check "Safety Thermostats" In the air flow
not engage before the gas heat exchanger.
+ Check the free movement of the fan wheel
+ Check the supply temperature limitation thermostats
+ Check gas low pressure switch
Nothing + Check electrical connection on the gas
happens Ignition Control Block and on
connection board
+ Check the fan voltage supply voltage
+ Check the fire-up electrode
Continuous + Check the pressure drop at the pressure
ventilation switch : It must be higher than 165 Pa
happens + Check the good operation of the pressure
without sparks switch using an Ohmmeter and by artificially
from fire-up creating a depression in the tube.
electrode + Check the operation the Backfire thermostat.
After 4 seconds + Check injection pressure during start-up
the GAS burner (value for High Heat)
still not operating + Check the supply voltage to the ignition
and safety shutdown control box (continuous voltage)
by the ignition + Remove the control box from the gas block.
Control Block.
Within 4 seconds + Check that the High / Low control is
the GAS burner connected (for valve VK 4125 P).
fires-up BUT + Check the position and connections of the
safety shutdown Ionisation Probe. It must not be Earthed (230 V) + Adjust the supply and
from the ignition + Check the Polarity of the 230 V connection
Control Block. on the gas burner transformer.
+ Measure the Ionisation Current : It must be
higher than 1,5 microAmps.
+ Check the type of gas.
ACTION
FAULT
POSSIBLE
SOLUTION
Replace
component
+ Replace thermostat
+ Open gas supply
+ Replace connection
board if necessary
+ Re-position the pressure
switch tube
+ Change the pressure
switch
+ Reset or replace the
Thermostat
+ 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.
+ Change the gas valve.
+ Check the whole
electrical supply.
injection pressure if gas is
different from natural
gas G20 : ( G25 gas of
Groningue for example).