appliance not connected to the common vent sys- tem. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will oper- ate at maximum speed. Do not operate summer exhaust fan. Close fireplace dampers.
d)Place in operation the appliances being inspected. Follow the manufacturers instructions for lighting each appliance. Adjust thermostat so appliance will operate continuously.
e)Test for natural draft (negative pressure) 12" above the outlet elbow after 5 minutes of main burner operation. Use the flame of a match or can- dle, or smoke from a cigarette, cigar or pipe, toilet paper trick.
f)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 other gas burning appliances to their previous conditions of use.
g)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, in Canada, the lat- est edition of CSA B149 Installation Code for Gas Burning Appliances and Equipment.
When
Fig. 22: Horizontal
Condensing Heat Exchanger (Category III)
Table L: Horizontal
Condensing Heat Exchanger (Category III)
30
