Utica Boilers UB90-100 Installationsanweisungen

2

See

 Tables #1 and #2 for specifi c high altitude orifi ce information.

Gas Conversion Procedure
When changing from Natural to Propane or vice 

versa, use correct conversion orifi ce for boiler 

model. 

Turn off manual gas valve.

Remove front door. Use 5/16” nut driver to 

remove top panel. 

Use 9/64” Allen wrench to remove adapter 

block from gas valve. Take care not to lose 

o-ring under the block.  See Figure #3.

Use adjustable or 1¼” wrench on bushing 

to remove gas orifi ce assembly from mixer 

turning counter clockwise.  Do not use 

channel locks, pipe wrench, etc, as damage 

to bushing may occur.  See Figure #2. 

Use small pipe wrench to remove orifi ce 

from bushing by turning counter clockwise. 

Install correct orifi ce for boiler being 

converted. Apply small amount of pipe dope 

to threads of orifi ce leaving last two threads 

clean. Turn clockwise into bushing.

Altitude in Ft.

0-5,000

5,000-10,000

Normal Input (MBH)

50

–

–

–

–

–

Combustion Setting (CO

2

)

8.7 - 9.7%  (CO 

< 100 ppm)

Gas Orifi ce

43331094

Burner Plate

109006405

Altitude in Ft.

0-5,000

5,000-10,000

Normal Input (MBH)

75

–

–

–

–

–

Combustion Setting (CO

2

)

8.7 - 9.7%  (CO 

< 100 ppm)

 Gas Orifi ce

43331092

Burner Plate

109006406

Altitude in Ft.

0-5,000

5,000-10,000

Normal Input (MBH)

100

–

–

–

–

–

Combustion Setting (CO

2

)

8.7 - 9.7%  (CO 

< 100 ppm)

Gas Orifi ce

43331090

Burner Plate

109009105

PRESSURE

REFERENCE PRESSURE

4-WAY CONNECTOR

PRESSURE REGULATOR

ADJUSTMENT

(UNDER COVER SCREW)

GAS VALVE VENT

OUTLET PRESSURE TAP

(1/8" PLUG)

DIFFERENTIAL
PRESSURE
GAUGE

TO PRESSURE SWITCH

WHITE TRANSPARENT
VINYL TUBING

U-TUBE
MANOMETER

BUSHING

MIXER