LAARS U.H.E. - Installation Manual - Manual (Page 13)

3. If the water heater is installed as a direct vent (outside air piped directly to the water heater), then additional
opening, other than the opening for the air intake, are not required. However, adequate ventilation air must
be provided in all cases to prevent increased room temperature.
CHEMICAL VAPOR CORROSION
Corrosion of the flue ways and vent system will occur if air for combustion contains certain chemical vapors.
Such corrosion may result in poor combustion and create a risk of asphyxiation, as well as reducing the life of the
water heater. Spray can propellants, cleaning solvents, refrigerator and air conditioning refrigerants, swimming
pool chemicals, calcium and sodium chloride, waxes and process chemicals are corrosive. Products of this sort
should not be stored near the water heater or outside by the air intake (if applicable).
TYPICAL INSTALLATION ILLUSTRATION
CAUTION
If the building cold water supply has a back-flow preventer, check valve or water meter with check valve provisions
for thermal expansion of water in the hot water system must be provided.
Figure 4. Typical Front Inlet Connection
Figure 5. Typical Front Inlet Connect with Storage Heater
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