Condition
Possible cause
Action
Faulty fuel/air ratio.
Adjust.
Faulty combustion head
adjustment.
Check and adjust.
Nozzle dirty or blocked.
Clean or change.
Too low ignition load.
Check.
Burners with ignition pilot gas valve, ignition flame does not form
Condition
Possible cause
Action
Fan motor starts, ignition is in
order. After a short time lockout
occurs.
Gas valve 1 or ignition gas
valve(s) do not open or open too
slowly.
Incorrect ignition gas valve setting Adjust ignition gas valve.
Faulty actuator.
Change faulty part.
Cable damaged.
Change.
Break in valve control circuit.
Find out cause of the break.
Lockout occurs after flame establishment
Condition
Possible cause
Action
Flame forms. Lockout occurs.
Gas pressure unstable.
Check and repair.
Incorrect burner adjustment
Adjust.
When burner runs to full load,
flame extinguishes, shutdown
occurs and then re-start.
Gas pressure too low because
min. gas pressure switch released.
Check operation and regulations.
Blocked filter
Clean or replace filter.
Flame monitoring fault, lockout
Condition
Possible cause
Action
Lockout during pre-purge.
Faulty flame detector
Change.
Faulty burner control
Check fault code. Replace.
Incorrect flame signal because of
extraneous light
Block extraneous light.
Flame forms. Lockout during
ignition phase or in normal
operation.
Incorrect flame detector position
Repair.
Dirty flame detector
Clean.
Flame too weak (light)
Check burner adjustments.
Faulty flame detector
Change.
Faulty burner control
Check fault code. Replace.
Lockout in shut-down period.
Faulty flame detector
Change.
Faulty burner control
Check fault code. Replace.
Incorrect flame signal because of
extraneous light
Block extraneous light.
Diffuser disc overheated due to
too low minimum capacity.
Adjust minimum capacity.
Diffuser disc overheated due
to too low pressure drop in
combustion head.
Adjust pressure loss.
Gas use:
Lockout during shutdown period
Flame does not extinguish: leaking
gas valves.
Replace.
M4263 2206EN
99 (102)