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Closed system/thermal expansion, Temperature and pressure relief valve, Warning – Kenmore 153:331472 User Manual

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Closed System/Thermal Expansion

Property Damage Hazard

All water heaters eventually leak

Do not install without adequate drainage.

As water is heated, it expands (thermal expansion). In a closed

system, the volume of water will grow. 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 build up. The temperature-pressure relief valve

is not intended for the constant relief of thermal expansion. This

condition is not covered under the limited warranty.

A properly sized thermal expansion tank should be installed

on all closed systems to control the harmful effects of thermal

expansion. Thermal expansion tanks are available from Sears

stores and through the Sears Service Centers. Contact the

local plumbing inspector, water supplier and/or the Sears

Service Center for assistance in controlling these situations.

(For additional information, see the Troubleshooting Guide later

in this manual.)

Temperature and Pressure Relief Valve

A

warning

Explosion Harzard

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.

For protection against excessive pressures and temperatures,

a temperature and pressure relief valve must be installed in the

opening marked “T & P RELIEF VALVE.” (See Figure 24). 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

for Relief Valves for Hot Water Supply Systems, ANSI Z21.22.

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 rating plate.

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 & 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 rating plate of the water heater.

The Discharge Line:

• Must not be smaller than the pipe size of the relief valve or

have any reducing coupling installed in the discharge line.

• Must not be capped, blocked, plugged or contain any valve

between the relief valve and the end of the discharge line.

• Must terminate a maximum of six inches above a floor

drain or external to the building.

• Must be capable of withstanding 250°F (121°C) without distortion.

• Must be installed to allow complete drainage of both the

valve and discharge line.

T&P Relief Valve and Pipe Insulation

1. Locate the T&P Relief Valve on the water heater.

2. Locate the slit running the length of the insulation.

3 Spread this slit open and slip it up under the T&P Relief

Valve. See Figure 25. Apply gentle pressure to the insulation

to ensure it is fully seated on the T&P Relief Valve. Once

sealed secure the insulation with a section of tape.

IMPORTANT: The insulation or tape should not block or

cover the T&P Relief Valve drain opening. Also the insulation

or tape should not block or hinder access to the T&P Relief

Valve manual relief lever.

4. Next locate the hot water (outlet) & cold water (inlet) pipes to

the water heater.

5. Select one of the sections of pipe insulation and locate the slit

that runs the length of the insulation.

6. Spread the slit open at the base of the insulation and slip it

over the cold water (inlet) pipe. Apply gentle pressure along

the length of the insulation to ensure it is fully seated around

the cold water pipe. Also ensure that the base of insulation is

flush with the water heater. Once seated, secure the insulation

with a section of tape.

7. Repeat steps 5 through 6 for the hot water (outlet) pipe.

FIGURE 24.

2 1