Fig. 4: Venting Minimum Clearances
WARNING: These heaters must not be connected into any portion of mechanical draft systems operating under positive pressure. To do so may cause the flue products to be discharged into the living space causing serious health injury.
Common Vents
Manifolds that connect more than one heater to a com- mon chimney must be sized to handle the combined load. Consult available guides for proper sizing of the manifold and the chimney. At no time should the area be less than the area of the largest outlet.
At the time of removal of an existing heater, 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.
(a)Seal any unused openings in the common venting system.
Fig. 5: Common Venting
(b)Visually inspect the venting system for proper size and horizontal pitch and determine there is no blockage or restriction, leakage, corrosion and other deficiencies which could cause an unsafe condition.
(c)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.
(d)Place in operation the appliance being inspected. Follow the lighting instructions. Adjust tankstat so appliance will operate continuously.
(e)Test for spillage at the draft hood 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.
(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 any other gas burning appliance to their previous conditions of use.
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