Kenmore 31813 Owners Manual - Page 20

Troubleshooting Start Up Conditions Guide THERMAL EXPANSION Water supply systems may, because of such events as high line pressure, frequent cut-of_, the effects of water hammer among others, have installed devices such as pressure reducing valves, check valves, back flow preventers, etc._to control these types of problems. When these devices are not equipped with an internal by-pass, and no other measures are taken, the devices cause the water system to be dosed. As water is heated, it expands (thermal expansion) and dosed systems do not allow for the expansion of heated water. The water within the water heater tank expands as it is heated and increases the pressure of the water system. If the relieving point of the water heater's temperature-pressure relief valve is reached, the valve will relieve the excess pressure. The temperature-pressure relief valve is not intended for the constant relief of thermal expansion. This is an unacceptable condition and must be corrected. It is recommended that any devices installed which could create a closed system have a by-pass and/or the system have an expansion tank to relieve the pressure built by 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. Thermal Expansion Tank Specifications Model Number 153.331020 153.331050 _hnk Capacity In Gallons 2 5 Dimensions in Inches Pipe Fitting Diameter Length On "Ihnk 8 inches 12Y4inches Yi' Male 11 inches 14Y4inches Yi' Male HOT COLD WATER HEATER - COLD WATER , INLET FITTING (0 EXPANSION TANK (3) PRESSURE REDUCING VALVE WITH BY-PASS (z) PRESSURE GAUGE WATER SHUTOFF RECOMMENDED INSTALLATION (VERTICAL MOUNTING) WATER HEATER COLD WATER INLET FITTING HOT COLD FLOOR, CEILING JOIST, ETC. STRAPPING (0 EXPANSION TANK (3) PRESSURE REDUCING VALVE WITH BY-PASS INLET COLD WATER SHUTOFF Expansion Tank Sizing Chart Expansion "lank Capacity Needed Inlet* Water Pressure 40psi 50psi 60psi 70psi 80psi Water Heater Capacity (Gallons) 27 30 40 50 66 2 2 2 2 5 2 2 2 2 5 2 2 2 5 5 2 2 2 5 5 2 2 5 5 5 *Highest recorded inlet water pressure in a 24 hour period or regulated water pressure. NOTE= Expansion tanks are pre-charged with a 40 psi air charge. If the inlet water pressure is higher than 40 psi, the expansion tank's air pressure must be adjusted to match that pressure, but must not be higher than 80 psi. PRESSUREGAUGE ALTERNATE RECOMMENDED INSTALLATION (HORIZONTAL MOUNTING) STRANGE SOUNDS Possible noises due to expansion and contraction of some metal parts during periods of heat-up and cool-down do not represent harmful or dangerous conditions. 20