Dunkirk XEB II Series, Installation, Operation & Maintenance Manual

12

Removing Existing Boiler From Common Venting 
System

When an existing boiler is removed from a common 

venting system, the common venting system is likely to be 

too large for proper venting of the appliances remaining 

connected to it.
At the time of removal of an existing boiler, the following 

steps shall be followed with each appliance remaining 

connected to the common venting system placed in 

operation, while the other appliance remaining connected 

to the common venting system are not in operation.

1. 

Seal any unused openings in the common venting   

system.

2. 

Visually inspect the venting system for proper size and 

horizontal pitch and determine there is no blockage or 

restriction, leakage, corrosion and other de

fi

 ciencies 

which could cause an unsafe condition.

3. 

Insofar as is practical, close all building doors and 

windows and all doors between the space in which the 

appliances remaining connected to the common venting 

system are located and other spaces of the building. 

Turn on clothes dryers and any appliance not connected 

to the common venting system. Turn on any exhaust 

fans, such as range hoods and bathroom exhausts, so 

they will operate at maximum speed. Do not operate a 

summer exhaust fan. Close 

fi

 replace dampers.

4. 

Place in operation the appliance being inspected. Follow 

the lighting instructions. Adjust thermostat so appliance 

will operate continuously.

VENT INSTALLATION

5. 

Test for spillage at the draft hood relief opening after 5 

minutes of main burner operation. Use 

fl

 ame of a match 

or candle, or smoke from a cigarette, cigar, or pipe. 

6. 

After it has been determined that each appliance 

remaining connected to the common venting system 

properly vents when tested as outlined above, return 

doors, windows, exhaust fans, 

fi

 replace dampers and any 

other gas-burning appliance to their previous conditions 

of  use.

7. 

Any improper operation of the common venting sys-

tem should be corrected so the installation conforms 

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

54.  When re-sizing any portion of the common venting 

system, the common venting system should be re-sized 

to approach the minimum size as determined using the 

appropriate tables in Chapter 13 of the National Fuel 

Gas Code, ANSI Z223.1/NFPA 54.

8. 

It is recommended that existing gas vents be checked 

to be sure they meet local codes.