Kenmore 33968 Owners Manual - Page 23

Start Uj_ Conditions Thermal Expansion 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. Property Damage Hazard + Avoid water heater damage. - Install thermal expansion tank or device if necessary. • Contact qualified installer or service agency. HOT COLD / r=====_-m _ _ WATER HEATER COLDWATER iNLET FiTTiNG (3) PRESSURE REDUCING Water supply system may, because of such events as high line pressure, frequent cut-offs and the effects of water hammer 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 closed. As water is heated, it expands (thermal expansion) and closed 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 water heater's temperature-pressure relief valve is reached, the valve will relief 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 or device 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, see Figure 27. I (z) PRESSURE GAUGE WATER SHUT-OFF =RECOMMENDED iNSTALLATiON _VERTICAL MOUNTING) WATER HEATER COLD WATER iNLET \ FiTTiNG OT COLD FLOOR, CEILING JOIST, ETC. _ STRAPPING I -- EXPANSION d/ PRESSURE / GAUGE t iNLET COLD WATER SHUT-OFF ALTERNATE RECOMMENDED INSTALLATION -- (HORIZONTAL MOUNTING) Thermal Expansion Tank Specifications Mode! Number 153.331020 153.331050 Tank Capacity In Gallons 2 5 Dimensions in Inches Pipe Fitting Diameter Lentth On Tank 8 (203 mm) 12-3/4 (323 mm) 3/4" Male 11 (279 mm) 14-3/4 (375 mm) 3/4" Male FIGURE 27. 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. Expansion Tank Capacity Needed Expansion Tank Sizing Chart Inlet* Water Pressure 40psi 50psi 60psi 70psi 80psi Water Heater Capacity (Gallons 30 40 50 66 82 2 2 2 5 5 2 2 2 5 5 2 2 5 5 5 2 2 5 5 5 2 5 5 5 5 *Highest recorded inlet water pressure in a 24 hour period or regulated water pressure. Condensation causes sizzling and popping within the burner area during heating and cooling periods and should be considered normal. See Condensation section. Draft Hood Operation Check draft hood operation by performing a worst case depressurization of the building. With all doors and windows closed, and with all air handling equipment and exhaust fans operating such as furnaces, clothes dryers, range hoods and bathroom fans, a match flame should still be drawn into the draft hood of the water heater with its burner firing. If the flame is not drawn toward the draft hood, shut off water heater and make necessary air supply changes to correct. 23