Utica Boilers UB90-200 Installationsanweisungen

Turn off boiler power. Shut off gas supply to boiler.

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.

Reassemble burner assembly, turn gas supply and 

boiler power back on, relight boiler.

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.

Check for proper gas supply pressure and proper gas 

line sizing to boiler. Refer to “Check Gas Supply” on 

page 22.

Check for orifice in negative pressure hose at gas 

valve, and 2” air intake pipe upstream of gas valve.

Relight boiler.

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.

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.

If burner pulsation continues or boiler fails to light after 

performing above procedures, contact technical service 

for assistance.