Venting Instructions - American Water Heater 520 Installation Manual And Owner's Manual

On-demand condensing water heater, direct vent indoor and outdoor models

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Table Of Contents

Table of Contents

The 520 Indoor models are equipped with a thermistor and hi-limit switch for the exhaust gas, detecting

excess temperatures within the flue and enabling the unit to safely stop operations if needed. These

components are always monitoring exhaust gas conditions in order to prevent heat damage to PVC

(Plastic) venting if PVC is used.

If the exhaust gas temperature exceeds 140°F, these components will enable the unit to safely stop

operations. (For the 520 Outdoor model, these components are not available since there's no exhaust

venting required.)

520 Indoor model requires a 4" make-up intake air

supply pipe. The intake pipe must be sealed airtight.

Air supply pipe can be made of ABS, PVC,

galvanized steel, corrugated stainless steel,

or Category lll / IV stainless steel.

Sidewall venting is recommended for the

520 Indoor models. Vertical venting (roof

termination) is acceptable.

The

manufacturer

running the exhaust vent and the

intake pipe as parallel as possible.

The PVC adaptor is used to make the

connection between the 520 Indoor

vent collar and PVC vent pipe easier

and for maintenance purposes.

Improper venting of this appliance can result in excessive levels of carbon monoxide

which can result in severe personal injury or death.

WARNING

When installing the vent system, all applicable national and local codes must be

followed. If you install thimbles, fire stops or other protective devices and they

penetrate any combustible or noncombustible construction, be sure to follow all

applicable national and local codes.

The 520 Indoor models must be vented in accordance with the section "Venting of Equipment" of the

latest edition of the National Fuel Gas Code: ANSI Z223.1/NFPA 54 in the United States and/or Section 7

of the CAN/CSA B149.1 Natural Gas and Propane Installation Code in Canada, as well as applicable local

building codes.

The use of venting materials approved for Category III/IV appliances is recommended whenever possible.

However, 520 Indoor may also be vented with plastic pipe materials such as PVC. For details, please

refer to the Exhaust Vent (PVC Vent) section on p. 11. Vent installations in Canada which utilize plastic

vent systems must use venting that complies with ULC S636.

520 Indoor model INSTALLATION

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