Dunkirk Q90-200 Series II - Manual (Page 30)

30
11 - STARTUP
If Burner Appears To Pulsate During Ignition:
1.
Turn off boiler power. Shut off gas supply to boiler.
2.
Take burner assembly apart by removing combustion
air blower and gas valve/venturi assembly from boiler.
Visually inspect inside of burner. Look for debris (PVC
shavings, etc.). Remove debris if present.
3.
Reassemble burner assembly, turn gas supply and
boiler power back on, relight boiler.
If Burner Continues To Pulsates Or Fails To Light:
1.
Check for proper vent, intake pipe sizing, proper
vent lengths and vent configuration. Refer to “Safe
Installation And Operation” on page 6 and “Combustion
Air/ Vent Requirements” on page 16.
2.
Check for proper gas supply pressure and proper gas
line sizing to boiler. Refer to “Check Gas Supply” on
page 22.
3.
Check for orifice in negative pressure hose at gas
valve, and 2” air intake pipe upstream of gas valve.
4.
Relight boiler.
5.
If boiler still does not light,
A. Disconnect air inlet pipe. Allow boiler to start, verify
boiler firing rate and combustion properties.
B. Disconnect inlet air pipe by removing PVC inlet
air piping from coupler located on air inlet of gas
valve/venturi assembly.
C. Relight boiler.
6.
Verify firing rate and combustion when boiler lights.
Refer to “Adjustments And Checkout” on page 35. If air
inlet piping was disconnected in step 4 (above), leave it
disconnected and make first adjustment. Reconnect air
inlet piping, then verify combustion CO
2
, adjust again if
necessary.
7.
If burner pulsation continues or boiler fails to light after
performing above procedures, contact technical service
for assistance.