Riello RDB2 - BURNER FAULT-FINDING

10
Note: before making any electrical checks or modifications, ensure the mains supply to the boiler is switched off.
Fault
Possible cause
Action
Burner will not start
Control box locked out
Press red reset button on burner
High limit stat tripped
Press red reset button on rear of control panel;
check function of boiler stat
System controls satisfied
Ensure that all controls are calling for heat
Blown fuse
Fit new fuse (5A); if problem persists, look for short
circuits in the wiring
Motor or pump seized
Check for rotation; replace as necessary
Burner starts but flame will not
establish
No oil supply
Check oil levels in storage tank; check for
adequate flow through the oil supply pipes
Air trapped in pump or oil line
Bleed excess air from the pump via the pressure
gauge connection
Solenoid coil not opening
Check coil for continuity; replace as necessary
Blocked nozzle
Replace the nozzle
Electrodes incorrectly set
Reset gap and position to dimensions given
Electrode insulation cracked
Replace as necessary
Faulty ignition leads
Replace as necessary
Low oil pressure
Check pump pressure and adjust to level given
Flame establishes but cuts out after
a few seconds
Oil contaminated with water
Run oil from drain cock at tank until free of water
Oil filter partially blocked
Wash filter clean with kerosene
Faulty photocell or photocell not seeing
flame
Clean photocell; check for damage; ensure it is
fully inserted; replace as necessary
Low oil pressure
Check pump pressure and adjust
Morning start lock-out
Faulty non-return valve or air leak
Replace non-return valve; repair leak
Low voltage to the boiler
Check with electricity supplier to remedy
Incorrect combustion settings
Check combustion under normal running
conditions; set air intake and oil pressure
Oil in storage tank below level of burner
Raise tank or fit two-pipe oil supply
Delayed ignition (burner pulsates)
Nozzle partially blocked
Replace nozzle
Low oil pressure
Check pump pressure and adjust
Flue blocked or damaged
Check flue; replace/repair as necessary
Fan slipping on shaft
Check fan; replace/repair as necessary
Pump coupling loose or worn
Check coupling; replace/repair as necessary
Burner starts violently
Electrodes incorrectly set
Reset electrode gap and position to dimensions
given in burner details leaflet
Electrodes damaged
Replace as necessary
Faulty ignition leads
Replace as necessary
Burner repeatedly attempts to fire
(balanced-flue only)
Exhaust gas in combustion air
Repair/replace leaking flue sections as necessary;
check for obstructions close to the terminal
Combustion fumes smell
Combustion chamber access cover not
secure
Tighten nuts; replace seal as necessary
Burner incorrectly fitted or gasket
damaged
Tighten burner to boiler; replace seal as necessary
Flue incorrectly fitted or gasket damaged
Tighten mounting nuts; replace seal as necessary
BURNER FAULT-FINDING