331551-002
– 17 –
installation of the valves (see Figure 11). Before changing the
factory setting on the thermostat, read the "Water Temperature
Regulation" section in this manual.
MIXING VALVE
NON-TEMPERED
WATER SUPPLY
TEMPERED
POTABLE WATER
SHUT-OFF
VALVE
COLD-WATER
INLET
NON-TEMPERED
WATER RETURN
Figure 11. Suggested Plumbing Connections For
Mixing Valve Installation
Closed System/Thermal Expansion
Water supply systems may, because of code requirements
or such conditions as high line pressure, among others, have
installed devices such as pressure reducing valves, check
valves, and back fl ow preventers. Devices such as these
cause the water system to be a closed system. As water is
heated, it expands (thermal expansion). In a closed system
the volume of water will grow when it is heated. As the volume
of water grows there will be a corresponding increase in water
pressure due to thermal expansion. Thermal expansion can
cause premature tank failure (leakage). This type of failure is
not covered under the limited warranty. Thermal expansion
can also cause intermittent Temperature-Pressure Relief Valve
operation: water discharged from the valve due to excessive
pressure buildup. This condition is not covered under the
limited warranty. The Temperature-Pressure Relief Valve is
not intended for the constant relief of thermal expansion. A
properly sized thermal expansion tank must be installed on
all closed systems to control the harmful effects of thermal
expansion. Contact a local plumbing service agency to have
a thermal expansion tank installed.
Important:
Do not plug or remove the temperature and
pressure relief valve.
Temperature And Pressure (T&P) Relief Valve
•
Temperature-pressure relief
valve must comply with ANSI
Z21.22-CSA4.4 and ASME
code.
•
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
•
Do not plug, block, or cap the
discharge line.
•
Failure to follow this warning
can result in excessive tank
pressure, serious injury or
death.
Explosion Hazard
WARNING
For protection against excessive pressures and temperatures,
a temperature and pressure relief valve must be installed
in the opening marked “T&P RELIEF VALVE”. This valve
must be design certified by a nationally recognized testing
laboratory that maintains periodic inspection of the production
of listed equipment or materials as meeting the requirements
of the
“Standard For Relief Valves For Hot Water Supply
Systems”, ANSI Z21.22/CSA 4.4”
. The function of the
temperature and pressure relief valve is to discharge water
in large quantities in the event of excessive temperature or
pressure developing in the water heater. The valve’s relief
pressure must not exceed the working pressure of the water
heater as stated on the data plate.
A T&P valve is either installed or supplied loose with this
water heater.
Important:
Only a new temperature and pressure relief valve
should be used with your water heater. Do not use an old or
existing valve as it may be damaged or not adequate for the
working pressure of the new water heater. Do not place any
valve between the relief valve and the tank.
The Temperature And Pressure Relief Valve:
•
Must not be in contact with any electrical part.
•
Must be connected to an adequate discharge line.
•
Must not be rated higher than the working pressure shown
on the data plate of the water heater.
