If this water heater is installed in a closed water supply system, such as one having a back-flow preventer in the cold water supply line, means shall be provided to control thermal expansion. Contact the water supplier or local plumbing inspector on how to control this situ- ation.

When this water heater system is supplying general purpose hot water requirements for use by individuals, a thermostatically controlled mixing valve is recom- mended to reduce the risk of scald injury. Contact a licensed plumber or the local plumbing authority for further information.

Thermometer(s) should be installed so that they indi- cate the water temperature at or near the outlet of the storage tank.

Relief Valve

A new combination temperature and pressure (T & P) relief valve, complying with the Standard for Relief

Valves and Automatic Gas Shut Off Devices for Hot Water Supply Systems, ANSI Z21.22, must be installed in the opening provided on top of the storage tank, at the time of installation. No valve is to be placed between the relief valve and the storage tank.

The pressure rating of the relief valve must not exceed the 160 maximum working pressure indicated on the water heater rating plate. The BTUH rating of the relief valve must not be less than the BTUH input of the heater.

Connect the outlet of the relief valve to a suitable open drain. The discharge line must pitch downward from the valve to allow complete draining (by gravity) of the relief valve and discharge line. The discharge line should be no smaller than the outlet of the valve. The end of the discharge line should not be threaded or concealed, and should be protected from freezing. No valve of any type, restriction or reducer coupling, should be installed in the discharge line. Local codes shall govern installation of relief valve.

FLOW SWITCH

PRV

RATING PLATE

ON/OFF

SWITCH

ELECTRICAL

CONTROLS

LOCATION

INLET/OUTLET

WATER

CONNECTIONS

OPTIONAL

PUMP

COMBINATION

GAS VALVE

HIGH LIMITS

PILOT LOCATION

Fig. 14: 0261 Low NOx WH1 with Pressure Relief Valve

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Raypak 2600401 operating instructions Low NOx WH1 with Pressure Relief Valve