Utica Boilers UB90-200 Installationsanweisungen

Connections And Termination
Installation must conform to requirements of authority 

having jurisdiction or, in absence of such requirements, 

to the section for Air for Combustion and Ventilation of 

the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/

or Natural Gas and Propane Installation Code, CAN/CSA 

B149.1.

Installer must clean and remove all shavings from interior 

of all pipes used on air intake to prevent damage to gas 

burner and ensure proper operation.

Boilers require dedicated direct vent system. All air for 

combustion is taken directly from outdoors through 

combustion air intake pipe. All flue products are discharged 

to outdoors through vent pipe.  Install vent system in 

accordance with instructions in this manual.

Figures 8 and 9 “Combustion Air and Vent Pipe 

Requirements, for standard two-pipe roof and sidewall 

terminations and Figures 10, 11, and 12 for concentric 

vent terminations (roof termination is preferred). 

Combustion air and vent pipes must terminate together in 

same atmospheric pressure zone as shown. Construction 

through which vent and air intake pipes may be installed 

is minimum ¼” and maximum 24” thickness.

Combustion air and vent pipe fittings must conform 

to one of the following American National Standards 

Institute (ANSI) and American Society for Testing and 

Materials (ASTM) standards:

Combustion air and vent piping connections on boiler 

are 2”, but must increase to 3”. Due to potential for 

flue gas temperatures over 155°F, first 5 feet of vent 

pipe must be CPVC (furnished), remaining vent pipe 

can be PVC. This requirement is not required when 

using PP. If any elbows are employed within first 2½’ 

of vent, they must be CPVC. Two 30” pieces of 2” CPVC 

pipe and one 2” CPVC coupling are furnished with 

boiler. See Figure 13.

Length of pipe is counted from boiler jacket (air intake 

pipe) or from vent tee (vent pipe). First five feet of “Total 

Equivalent Length” of vent pipe must be CPVC.  This 

requirement is required when using PP.
Reduce maximum vent length 5 feet per each additional 

elbow.

Pitch horizontal combustion air and vent piping back 

to boiler at minimum ¼” per foot (21mm/m) from 

intake and vent terminals so all moisture in combustion 

air and vent piping drains to boiler. Pitch pipes 

continuously with no sags or low spots where moisture 

can accumulate and block flow of air or flue gas. This 

blockage may cause combustion instability, noise and 

lead to nuisance control lockouts.

Combustion air and vent pipes must be airtight, 

watertight and tested for leaks.

Use of cellular core PVC (ASTM F891), cellular core 

CPVC, or Radel

®

 (polypenolsulfone) in venting 

system could result in death, serious injury.

  

6 ft. (1.8 m) in length

60 ft. (18.3 m) in length and 

up to four (4) 90° elbows  

1 - 90° elbow = 5 ft (1.6 m)

1 - 45° elbow = 3.5 ft (1.1 m)

1- 2” x 3” adapter = 0 ft (0 m)
   All field installed vent pipe must be 3”

* Past first 2” section provided with boiler