John Wood JW375T75N-AV, Instruction Manual

Page: 23 / 36

23
It is recommended that the Temperature-Pressure Relief Valve
should be checked to ensure that it is in operating condition every
6 months.
When checking the Temperature-Pressure Relief Valve operation,
make sure that (1) no one is in front of or around the outlet of the
Temperature-Pressure Relief Valve discharge line, and (2) that
the water discharge will not cause any property damage, as the
water may be extremely hot. Use care when operating valve as
the valve may be hot.
To check the relief valve, lift the lever at the end of the valve
several times, see Figure 20. The valve should seat properly and
operate freely.
If after manually operating the valve, it fails to completely reset
and continues to release water, immediately close the cold
water inlet to the water heater and drain the water heater, see
Draining And Flushing on page 25. Replace the Temperature-
Pressure Relief Valve with a properly rated/sized new one, see
Temperature-Pressure Relief Valve on page 11 for instructions
on replacement.
DISCHARGE PIPE
TEMPERATURE-PRESSURE
RELIEF VALVE
FIGURE 20.
If the Temperature-Pressure Relief Valve on the water heater
weeps or discharges periodically, this may be due to thermal
expansion.
NOTE: Excessive water pressure is the most common cause
of Temperature-Pressure Relief Valve leakage. Excessive
water system pressure is most often caused by “thermal
expansion” in a “closed system.” See Closed Water Systems
and Thermal Expansion on page 10. The Temperature-
Pressure Relief Valve is not intended for the constant relief of
thermal expansion.
Temperature-Pressure Relief Valve leakage due to pressure
build up in a closed system that does not have a thermal
expansion tank installed is not covered under the limited
warranty. Thermal expansion tanks must be installed on all
closed water systems.
DO NOT PLUG THE TEMPERATURE-PRESSURE RELIEF
VALVE OPENING. THIS CAN CAUSE PROPERTY DAMAGE,
SERIOUS INJURY OR DEATH.
Explosion Hazard
Temperature-Pressure Relief Valve
must comply with ANSI Z21.22-
CSA 4.4 and ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.
HOUSEKEEPING
Fire and Explosion Hazard
Do not obstruct combustion air
openings at the bottom of the
water heater.
Do not use or store flammable vapor
products such as gasoline, solvents
or adhesives in the same room or area
near water heater or other appliance.
Can cause serious injury or death.
Vacuum around base of water heater for dust, dirt, and lint on a
regular basis.
INSTALLED IN SUITABLE AREA: To insure sufficient ventilation
and combustion air supply, proper clearances from the water heater
must be maintained. See “Locating the New Water Heater” section.
Combustible materials such as clothing, cleaning materials, or
flammable liquids, etc. must not be placed against or adjacent to
the water heater which can cause a fire.
ANODE ROD INSPECTION
Property Damage Hazard
•
Avoid water heater damage.
•
Inspection and replacement of anode rod required.
CAUTION
The anode rod is used to protect the tank from corrosion. Most
hot water tanks are equipped with an anode rod. The submerged
rod sacrifices itself to protect the tank. Instead of corroding the
tank, water ions attack and eat away the anode rod. This does not
affect water’s taste or color. The rod must be maintained to keep
the tank in operating condition.
Anode deterioration depends on water conductivity, not necessarily
water condition. A corroded or pitted anode rod indicates high
water conductivity and should be checked and/or replaced more
often than an anode rod that appears to be intact. Replacement
of a depleted anode rod can extend the life of your water heater.
Inspection should be conducted by a qualified service agency, and
at a minimum should be checked annually after the warranty period.
Artificially softened water is exceedingly corrosive because the
process substitutes sodium ions for magnesium and calcium ions.
The use of a water softener may decrease the life of the water
heater tank.
The anode rod should be inspected after a maximum of three
years and annually thereafter until the condition of the anode rod
dictates its replacement.
NOTE: Artificially softened water requires the anode rod to be
inspected annually.
TEMPERATURE-PRESSURE RELIEF VALVE TEST
Burn hazard.
Hot water discharge.
Keep clear of Temperature-
Pressure Relief Valve
discharge outlet.