Riello DB3 SM C01 TC FS1 A0 T250, Installation, Use And Maintenance Instructions, Page: 40 / 64

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6
Maintenance
6.1 Problems and remedies
If the burner does not work properly, first you must:
1 check that the electric connections have been correctly performed;
2 ensure that the fuel is delivered correctly;
3 check that all the adjustment parameters (e.g. boiler water temperature or boiler steam pressure) are correctly set.
Fault Possible cause Recommended remedy
The burner does not start • No electrical power supply . . . . . . . . . . . . . . . . . . . .Close all switches - Check connec-
tions
• A limiter or safety control device is open. . . . . . . . . .Adjust or replace
• Flame control lock-out. . . . . . . . . . . . . . . . . . . . . . . .Reset control box
• Control box fuses blown . . . . . . . . . . . . . . . . . . . . . .Replace
• Erroneous electrical connections . . . . . . . . . . . . . . .Check connections
• Defective flame control . . . . . . . . . . . . . . . . . . . . . . .Replace
• No gas supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Open the manual valves between
meter and train
• Mains gas pressure insufficient. . . . . . . . . . . . . . . . .Contact your GAS COMPANY
• Minimum gas pressure switch fails to close . . . . . . .Adjust or replace
• Air pressure switch in operating position . . . . . . . . .Adjust or replace
The burner does not start and a
function lock out occurs • Flame simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . .Replace control box
The burner ignites but then
blocks Air pressure switch inoperative due to insufficient air pressure:
• Air pressure switch adjusted badly . . . . . . . . . . . . . .Adjust or replace
• Pressure switch pressure point pipe blocked . . . . . .Clean
is blocked
• Head wrong adjusted . . . . . . . . . . . . . . . . . . . . . . . .Adjust
The burner starts and then locks
out • Fault in flame detection circuit . . . . . . . . . . . . . . . . .Replace flame control
After pre-purge and safety time,
the burner goes to lock-out and
the flame does not appear • The solenoid VR allows little gas through . . . . . . . . .Increase
• Solenoid valves VR or VS fail to open . . . . . . . . . . .Renew the coil or rectifier panel
• Gas pressure too low . . . . . . . . . . . . . . . . . . . . . . . .Increase on the regulator
• Defective ignition transformer . . . . . . . . . . . . . . . . .Replace
• Erroneous valve or transformer electrical . . . . . . . .Repeat connections
connections
• Defective control box . . . . . . . . . . . . . . . . . . . . . . . .Replace
• A cock down-line of the gas train is closed . . . . . . . .Open
• Air in pipework . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bleed air
The burner goes to lock-out right
after flame appearance • The solenoid VR allows little gas through . . . . . . . . .Increase
• Max. gas pressure switch operates. . . . . . . . . . . . . .Adjust or replace
• Defective control box . . . . . . . . . . . . . . . . . . . . . . . .Replace
The burner repeats the starting
cycle without lock out • Mains gas pressure is near the value to which . . . . .Reduce operating pressure
the min. gas pressure switch gas is adjusted.. . . . . .of minimum gas pressure switch.
The repeated drop in pressure which follows . . . . . .Replace the gas filter cartridge
valve opening causes temporary opening of the
pressure switch itself, the valve immediately
closes and theburner comes to a halt. Pressure
increases again, the pressure switch closes again
and the firing cycle is repeated. The sequence
repeats endlessly. And so on.