Water Line Connections; Thermometers; Relief Valve - A.O. Smith 650A, 740A Installation & Operation Manual

ROBERTSHAW ® 7000 DERHC GAS CONTROL VALVE
FIGURE 10.

WATER LINE CONNECTIONS

Following are detailed installation diagrams for typical methods
of application for the water heaters.
The water heater may be installed by itself, or with a separate
storage tank, on both single and two-temperature systems.
When used with a separate storage tank, the circulation may be
either by gravity or by means of a circulating pump. When a
circulating pump is used it is important to note that the flow rate
should be slow so that there will be a minimum of turbulence
inside the heater.
If a water heater is installed in a closed water system, contact
the water supplier or local plumbing inspector on how to control
this situation.
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 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 water under supply
pressure.
SYSTEM CONNECTIONS
The system installation must conform to these instructions and
® Robertshaw is a registered trademark of the Robertshaw Controls
Company Corporation
CAUTION
to the local code authority having jurisdiction. Good practice
requires that all heavy piping be supported.
THERMOMETERS (Not supplied)
Thermometers should be obtained and field installed as shown
in the installation diagrams.
Thermometers are installed in the system as a means of
detecting the temperature of the outlet water supply.

RELIEF VALVE

This heater is equipped with an approved temperature and
pressure relief valve. ASME ratings cover pressure relief.
A.G.A ratings cover release rate with temperature actuation.
FOR SAFE OPERATION OF THE WATER HEATER, THE RELIEF
VALVE(S) MUST NOT BE REMOVED OR PLUGGED.
In addition to the appliance relief valve, each remote storage
tank that may be used in conjunction with this appliance shall
also be installed with a properly sized, rated and approved
temperature (ANSI) and pressure (ASME) relief valve(s). This
relief valve shall comply with the standard for relief valves and
automatic gas shut-off devices for hot water supply systems,
ANSI Z21.22/CSA 4.4.
Your local code authority may have other specific relief valve
requirements.
THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE
PRESSURE OR TEMPERATURE INTO THE STEAM RANGE, WHICH
MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, AND
SYSTEM OR HEATER DAMAGE. NO VALVE IS TO BE PLACED
BETWEEN THE RELIEF VALVE AND THE TANK.
A DRAIN LINE MUST BE CONNECTED TO THE RELIEF VALVE TO
DIRECT DISCHARGE TO A SAFE LOCATION TO AVOID SCALDING
OR WATER DAMAGE. THIS LINE MUST NOT BE REDUCED FROM
THE SIZE OF THE VALVE OUTLET AND MUST NOT CONTAIN
VALVES, RESTRICTIONS NOR SHOULD IT BE LOCATED IN
FREEZING AREAS. DO NOT THREAD OR CAP THE END OF THIS
LINE. RESTRICTED OR BLOCKED DISCHARGE WILL DEFECT
THE PURPOSE OF THE VALVE AND IS UNSAFE. DISCHARGE
LINE SHALL BE INSTALLED TO ALLOW COMPLETE DRAINAGE
OF BOTH THE VALVE AND LINE.
13
WARNING