User manual BOSCH GWH 425 EF

[. . . ] Water heaters for use with Natural and L. P. G. GWH 425 EF Flow Modulated with Electronic Ignition and Power Venting Suitable for heating potable water only - Not approved for space heating purposes (Intended for variable flow applications with steady cold water inlet temperatures) GWH-425-EF-N GWH-425-EF-L Warning: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Do not store or use gasoline or other flammable vapor and liquids in the vicinity of this or any other appliance. Improper installation, adjustment, alteration, service or maintenance can cause injury or property damage. For assistance or additional information consult a qualified installer, service agency or the gas supplier. [. . . ] For multiple appliances combine the total btu input load and then refer to applicable chart below. inches inches 1/4 3/8 1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4 0. 364 0. 493 0. 622 0. 824 1. 049 1. 380 1. 610 2. 067 2. 469 3. 068 4. 026 1650 1450 2700 2300 4700 4100 1270 1150 1050 2000 1850 1700 1600 1500 1400 3600 3250 3000 2800 2600 2500 1130 1050 2000 1850 1700 4, 100 3, 800 3500 17, 500 12, 000 9, 700 8, 300 7, 400 6, 80 6, 200 5, 800 5, 400 5, 100 4, 500 FOR LP GAS Maximum Capacity of Pipe in Thousands of BTU per Hour of Undiluted Petroleum Gases (at 11 inches Water Column Inlet Pressure) (Based on a Pressure Drop of 0. 5 Inch Water Column). Nominal Iron Pipe Size, Inches Black Iron Pipe Length of Pipe, Feet 10 20 30 40 50 60 70 96 80 89 90 83 100 78 162 307 630 976 125 69 146 275 567 866 150 63 132 252 511 787 1/2 3/4 1 1 1/4 1 1/2 2 275 189 152 567 693 315 107 732 590 220 149 121 330 229 185 622 433 346 129 114 103 267 237 217 196 185 173 504 448 409 378 346 322 103 913 834 771 724 677 155 141 127 118 108 102 299 264 239 220 204 192 1811 1606 1496 Maximum Capacity of Semi-Rigid Tubing in Thousands of BTU per Hour of Undiluted Liquified Petroleum Gases (at 11 inches Water Column Inlet Pressure) (Based on a Pressure Drop of 0. 5 Inch Water Column) Outside Diameter, Inch 3/8 1/2 5/8 3/4 7/8 Copper Length of Tubing, Feet 10 39 92 20 26 62 30 21 50 107 40 19 41 90 50 _ 37 79 131 198 60 _ 35 72 70 _ 31 67 80 _ 29 62 90 _ 27 59 95 100 _ 26 55 90 199 131 329 216 501 346 181 145 277 233 121 112 104 187 164 155 146 138 * Source National Fuel Gas Code NFPA 54, ANSI Z223. 1 - No Additional Allowance is necessary for an ordinary number of fittings 12 6 720 607 017 Connecting the pressure relief valve (PRV) WATER CONNECTIONS Install the heater centrally in the building if possible and make hot water piping runs as short as possible When facing the heater, the cold water inlet will be on the right and the hot water outlet on the left. . Although water piping throughout your structure may be other than copper, we recommend that copper piping be used for at least three feet before and after the heater (follow local codes if more stringent). Plastics or other PEX type plumbing line materials are not suitable for connecting directly to the water heater. Keep water inlet pipe to no less than ½" (19. 05mm) diameter to allow the full flow capacity. If the cold and hot connections to the heater are reversed, the heater will not function. The 425 EF is provided with one flexible type connector that must be connected to the cold inlet fitting of the water valve as shown in Fig. The union end of the flexible connector should be attached to the rear inlet port of the water valve with the supplied washer gasket. The ½" flexible hot water outlet line is supplied attached to the heater. Full port valves should be installed on both the cold water supply and hot water outlet lines to facilitate servicing the heater (see Fig. For installation on a private well system with the use of a pressure tank, the lowest pressure range setting recommended is 30-50 psi (2. 07-3. 45 bar). The listed pressure relief valve supplied with the heater must be installed at the time of installation. Should a discharge line be added to the PRV no valve is to be placed between the PRV and the heater. No reducing coupling or other restriction may be installed in the discharge line. The discharge line must be installed such that it allows complete drainage of both the PRV and the line. The location of the PRV must be readily accessible for servicing or replacement and be mounted as close to the water heater as possible. To install the PRV, a suitable fitting connected to an extension on a "T" fitting can be sweated to the hot water line. 8 - Plumbing and Pressure Relief Valve Fig. 7 - Water valve and water connectors, top view 6 720 607 017 13 ELECTRICAL CONNECTIONS WARNING: For safety reasons, disconnect the power supply to the heater before any service or testing is performed. WARNING: This heater must be electrically grounded in accordance with the most recent edition of the National Electrical Code, NFPA 70. In Canada, all electrical wiring to the heater should be in accordance with local codes and the Canadian Electrical Code, CSA C22. 1 Part 1. Do not rely on the gas or water piping to ground the metal parts of the heater. CAUTION: Label all wires prior to disconnection when servicing controls. The 425 EF requires an electrical power supply from 120VAC 60Hz circuit and must be properly grounded. - A means for switching off the 120 VAC power supply must be provided. [. . . ] The heat exchanger If the heat exchanger fails within fifteen (15) years after the original installation and operation CEC will furnish a replacement heat exchanger. However, if the water heater is installed in other than a single family dwelling this heat exchanger warranty is limited to two (2) years from date of original installation and operation. to defects or malfunctions resulting from failure to properly install, operate or maintain the unit in accordance with the printed instructions provided; 2. to damage or abuse, accident, neglect or freezing and other acts of nature; 3. [. . . ]