At the time of removal of an existing boiler, the follow- ing steps shall be followed with each appliance remaining connected to the common venting system placed in operation, while the other appliances remain- ing 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 make sure there is no blockage or restriction, leakage, corrosion and other deficiencies 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 com- mon 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 oper- ate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.
4.Place in operation the appliance being inspected. Follow the lighting instructions. Adjust thermostat so appliance will operate continuously.
5.Test for spillage at the drafthood relief opening after 5 minutes of main burner operation. Use the flame of a match or candle, or smoke from a ciga- rette, cigar or pipe to visually check spillage.
6.After it has been determined that each appliance remaining connected to the common venting sys- tem properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas burning appliance to their previous conditions of use.
7.Any improper operation of the common venting system should be corrected so that the installation conforms with the latest edition of the National Fuel Gas Code, ANSI Z223.1. When resizing any portion of the common venting system, the com- mon venting system should be resized to approach the minimum size as determined using the appropriate tables in the National Fuel Gas Code, ANSI Z 223.1 and CSA - B149.
Vent Damper Installation Location
The vent damper supplied with each boiler must be located in the vent so that it serves only the appliance for which it is intended.
If improperly installed, a hazardous condition, such as an explosion or carbon monoxide poisoning, could result. Make certain that it is mounted in an accessible location at least 6 in. (152.4 mm) from any combustible material or the heat exchanger and that the position indicator is in a visible location.
The vent damper must be installed at the appliance drafthood, and without modification of the drafthood. To connect the vent damper wiring to the boiler wiring, connect the damper circuit plug to the boiler circuit plug.
Fig. 7: Vent Damper Location
WARNING: Carefully read and follow the installation instructions furnished with the vent damper package. Failure to follow these instructions can cause asphyxiation, explosion or fire.
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