UTICA BOILERS UB90 125 Installation Manual And Operating Instructions page 22

IF BURNER APPEARS TO PULSATE DURING
IGNITION:
1. Turn off boiler power and shut off gas supply to the boiler.
2. Take the burner assembly apart by removing the com-
bustion air blower and gas valve/venturi assembly from the
boiler and visually inspect the inside of the burner. Look for
any debris (PVC shavings, etc.) and, if anything is present,
remove it.
3. Reassemble burner assembly, turn gas supply and boiler
power back on, and relight boiler.
IF BURNER STILL PULSATES OR FAILS TO
LIGHT:
1. Check for proper vent and intake pipe sizing and for proper
vent lengths and vent configuration by referring to Section V,
"Before Installing The Boiler," and Section VIII, "Combustion
Air and Vent Pipe," in this manual.
2. Check for proper gas supply pressure and proper gas line
sizing to the boiler by referring to section IX, "Gas Supply
Piping," in this manual.
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, the air inlet pipe may need to be
disconnected to allow the boiler to start in order to verify the
boiler firing rate and combustion properties. The inlet air pipe
can be disconnected by removing the PVC inlet air piping from
the Fernco fitting located on the air inlet of the gas valve/ven-
turu assembly. Relight boiler.
6. When the boiler lights, the firing rate and combustion
should be checked per the "Adjustments and Checkout" pro-
cedure in Section XIII of this manual. If the air inlet piping
was disconnected in step 4 (above), leave it disconnected
and make first adjustment. Then reconnect air inlet piping,
recheck combustion CO
7. If burner pulsation continues or boiler fails to light after
performing the above procedures, please contact Technical
Service at 1-800-325-5479 for further assistance.
, and adjust again if necessary.
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