Bradford White SW-2-40R-L Installation And Operating Manual page 27

Maintenance continued-
Before manually operating the valve, make sure that a drain line
has been attached to the valve to direct the discharge to an open
drain. Failure to take this precaution could mean contact with
extremely hot water discharging from the valve during this
checking operation.
If the temperature–pressure relief valve on the heater discharges
periodically or continuously, it may be due to thermal expansion
of water in a closed water supply system, or it may be due to a
faulty relief valve.
Thermal expansion is the normal response of water when it is
heated. In a closed system, thermal expansion will cause the
system pressure to build until the relief valve actuation pressure
is equaled. Then the relief valve will open, allowing some water to
escape, slightly lowering the pressure. Contact your water
supplier or local plumbing inspector on how to control this
situation.
ABOVE ALL, DO NOT PLUG THE TEMPERATURE AND
PRESSURE RELIEF VALVE. THIS IS NOT A SOLUTION AND
CAN CREATE A HAZARDOUS SITUATION.
3. Anode Inspection and Replacement – This water heater is
equipped with multiple sacrificial anodes. Anodes protect the
glass-lined tank from corrosion by sacrificing themselves through
electrolysis. When the anode material is consumed, there is no
more protection and corrosion of the tank accelerates.
Inspection of the anode every year allows you to identify a spent
anode and replace. Replace the anode when its diameter is 3/8
of an inch, or every other year, whichever is first. Aggressive,
very hot and softened water causes rapid consumption of the
anode, requiring frequent inspections. Anodes are available from
your distributor or from the manufacturer.
CAUTION
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