A.O. Smith BT- 65 warranty Venting, Relief Valve, System Connections, Draft Hood, Vent Connection

2.Toxic chemicals, such as those used for boiler treatment, shall NEVER be introduced into this system.

3.This unit may NEVER be connected to any existing heating system or component(s) previously used with a non-potable water heating appliance.

4.When the system requires water for space heating at temperatures higher than required for domestic water purposes, a tempering valve must be installed (See Fig. 3).

CAUTION

A closed system will exist if a check valve (without bypass), pressure reducing valve (without bypass), or a water meter (without bypass) is installed in the cold water line between the water heater and street main (or well).

Excessive pressure may develop in such closed systems, causing premature tank failure or intermittent relief valve operation. This is not a warranty failure. An expansion tank or a similar device may be required in the inlet supply line between the appliance and the meter or valve to compensate for the thermal expansion of the water.

SYSTEM CONNECTIONS

The system installation must conform to these instructions and to the local code authority having jurisdiction. Good practice requires that all heavy piping be supported.

VENTING

WARNING

THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST BE FOLLOWED TO AVOID CHOKED COMBUSTION OR RECIRCULATION OF FLUE GASES. SUCH CONDITIONS CAUSE SOOTING OR RISKS OF FIRE AND ASPHYXIATION.

Heater must be protected from freezing downdrafts.

Remove all soot or other obstructions from the chimney that will retard a free draft.

Type B venting is recommended with these heaters.

This water heater must be vented in compliance with all local codes, the current revision of the National Fuel Gas Code (ANSI-Z223.1) and with the Category I Venting Tables. In Canada, venting shall conform to the requirements of the current CAN/CSA B149.1-00 installation code.

If any part of the vent system is exposed to ambient temperatures below 35 degrees F (2 degrees C) it must be insulated to prevent condensation.

•Do not connect the heater to a common vent or chimney with solid fuel burning equipment. This practice is prohibited by many local building codes as is the practice of venting gas fired equipment to the duct work of ventilation systems.

•Where a separate vent connection is not available and the vent pipe from the heater must be connected to a common vent with an oil burning furnace, the vent pipe should enter the smaller common vent or chimney at a point above the large vent pipe.

FIGURE2

DRAFT HOOD

The draft hood furnished with this heater must be installed without alteration. Provision must be made if it is installed in confined space or a small room to accommodate draft hood spillage and avoid risks described in previous steps. The upper air opening called for in the AIR REQUIREMENTS section of this manual is for this purpose.

Locate draft hood as seen in Figure 1. Position draft hood over the flue tube. Align the draft hood legs with four holes surrounding the flue. Insert tabbed end of legs into the corresponding holes and twist to lock the draft hood in place.

When installing vent piping, secure the vent pipe to the draft hood using at least three sheet metal screws in the draft hood outlet.

VENT CONNECTION

Vent connections must be made to an adequate stack or chimney. Size and install proper size vent pipe. Do not reduce pipe size to less than that of the draft hood outlet.

Horizontal runs of vent pipe must have a minimum upward slope toward the chimney of 1/4 inch per foot (20 mm per meter). Dampers or other obstructions must not be installed in between the heater and the draft hood. Be sure that the vent pipe does not extend beyond the inside wall of the chimney.

Where a continuous or intermittent back draft is found to exist, the cause must be determined and corrected. A special vent cap may be required. If the back draft cannot be corrected by the normal methods or if a suitable draft cannot be obtained, a blower type flue gas exhauster must be employed to assure proper venting and correct combustion.

THERMOMETERS (Not Supplied)

Thermometers should be obtained and field installed.

Thermometers are installed in the system as a means of detecting the temperature of the outlet water supply.

RELIEF VALVE

This water heater is equipped with a combination temperature- pressure relief valve that complies with the standard for relief valves and automatic gas shut-off devices for hot water supply system, ANSI Z21.22, for Canada see CAN/CSA 149.1-00. FOR SAFE OPERATION OF THE WATER HEATER, THE RELIEF VALVE(S) MUST NOT BE REMOVED OR PLUGGED.

ASME ratings cover pressure relief capacities. A.G.A. ratings cover release rate with temperature actuation.

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