Raypak 260-401 Installation And Operating Instructions Manual page 12

When this water heater system is supplying general purpose hot water requirements for use by individuals, a
thermostatically controlled mixing valve is recommended 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 indicate 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.
261 LOW NOx
WH1
12
Fig # 9360