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INDOOR INSTALLATION
The water heater must be installed with service access in mind.
This heater must be supplied with sufficient quantities of non-contaminated air to support proper
combustion and equipment ventilation. Combustion air can be supplied via conventional means where
air is drawn from the area immediately surrounding the water heater (room sourced), or via direct vent,
where combustion air is drawn directly from outside (room sealed).
INSIDE AIR CONTAMINATION
All heaters experience some condensation during start-up. The condensate from flue gas is acidic.
Combustion air can be contaminated by certain vapours in the air which raise the acidity of the
condensate. Higher acidity levels attack many materials including stainless steel, which is commonly
used in high efficiency systems.
You may choose to use outside combustion air (room sealed option) for one or more of these reasons:
1. Installation is in an area containing contaminants listed below which will induce acidic
condensation.
2. Reduce infiltration into the building through openings and ventilation.
Products causing contaminated combustion air:
• spray cans containing chloro/fluorocarbons
• permanent wave solutions
• chlorinated waxes/cleaners
• chlorine-based swimming pool chemicals
• calcium chloride used for thawing
• sodium chloride used for water softening
• refrigerant leaks
• paint or varnish removers
• hydrochloric acid/muriatic acid
• cements and glues
• antistatic fabric softeners used in clothes dryers
• chloride-type bleaches, detergents, and cleaning
solvents found in household laundry rooms
• adhesives used to fasten building products
• similar products
Areas where contaminated combustion air commonly exists:
• dry cleaning/laundry areas
• metal fabrication plants
• beauty shops
• refrigeration repair shops
• photo processing plants
• auto body shops
• plastic manufacturing plants
• furniture refinishing areas and establishments
• new building construction
• remodelling areas
• open pit skimmers
Check for areas and products listed above before installing heater. If found:
• remove products permanently, OR
• install a room sealed fluing
system
