Gasmaster GMI 2M, Installation, Operation And Maintenance Manual

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IOM GMI 2M & 2ML Nov 2010.doc
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2.7.1
Periodically inspect the vent duct for pin holes or cracks. Maintaining gas tight seal is very
necessary and important. Please apply appropriate condensate sealant (Mill-Pac) on these
openings.
When an existing boiler or water heater 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. Therefore:
At the time of removal of an existing boiler or water heater, the following steps should be
followed with each appliance remaining connected to the common venting system placed in
operation, while the other appliances remaining connected to the common venting system are
not in operation
I:
Seal any unused openings in the common venting system.
II:
Visually inspect the venting system for proper size and horizontal pitch and
determine that there are no blockages, restrictions, leakages, corrosions or other
deficiencies, which could cause an unsafe connection.
III:
Any improper operation of the common venting system should be corrected, so the
installation conforms to the National Fuel Gas Code, ANSI Z223.1. When resizing
any portion of the common venting system, the common venting system should be
resized to approach the minimum size as determined using the appropriate tables in
Appendix G in the National Fuel Gas Code, ANSI Z223.1”.
IV:
To insulate the single wall duct against condensate corrosion, add about 1” mineral
wool insulation or equivalent all around. The insulation will also assist exhaust gas
draft.