Bosch Appliances Model GWH 425 manual

GWH 425 PN INDOOR MODEL Flow Modulat ed wit h Sta nding pilot Suit able for heat ing pot able wat er only - Not approved for spac e heat ing purposes (Intended for variable flow applications with steady cold water inlet temperatures) GWH- 425-P N-N GWH- 425-P N-L 6 720 608 03 4 US (0 6.05) AL Warning: If the informatio n in this ma nual is no t fol[...]

6 720 608 034 2 Index Index 1 Warning 2 2 Appliance d etails 3 2.1 GWH 425 PN specification s (Technica l data) 3 2.2 Unpacking t he GWH 425 PN heater 4 2.3 General ru les to follow for safe operation 4 2.4 Dimensions and installation clearances 5 3 Installation instruction s 6 3.1 Introduction 6 3.2 Proper location for installing your heater 6 3.3[...]

6 720 608 034 Appliance det ails 3 2 Applian ce deta ils 2.1 GWH 425 PN specifications (Technical data) Approved in US/Canada Capacity GWH 425 PN: 4.3 GPM Maximum o utput GWH 425 PN: 91 525 Btu/hr Maximum in put GWH 425 PN: 117 000 Btu/hr Efficiency in % Recovery efficiency 78% Min. Outp ut GWH 425 PN: 23 906 Btu/hr Gas Requi rement Gas conne ction[...]

6 720 608 034 4 Appliance de tails 2.2 Unpacking the GWH 425 PN heater This heater is packed secu rely. Before installing the unit, be certain you have th e correct heater for your type of Gas - Propane or Natural Gas. Ide ntification labels are found on the shipping box, and on the rating p late w hich is located on the right side panel of the c o[...]

6 720 608 034 Appliance det ails 5 2.4 Dimensions and installation clearances Fig. 3 Dimensions in Inches and ( mm) 4 Heat e xchange r 5 Burner 10 Tempe rature contro l 11 Water valve 20 Gas con necti on 26 Outpu t control 36 Front cover 37 Hole for fixing to wa ll 38 Exhau st pipe to wall 39 Draug ht diverte r with flue g as monitor 40 Gas v alve [...]

6 720 608 034 6 Installation instruction s 3 Installa tion ins tructio ns 3.1 Introduction Please follow t hese i nstructions. Failure to follow instructions may result in: B Damage or injury . B Improper operati on. B Loss of warrant y. If you are unable to perform the tasks required to install this heater properly, please contact a locally licens[...]

6 720 608 034 Installation instructio ns 7 3.4 Mounting Heater Remove co ver and ins pect. B Remove the te mperature con trol. B Unscrew the c over fixing scre ws, see Fig. 6 . B Remove the ou ter case by s liding it forwar ds and then lifting up wards. B Ensure that th e flue terminal is clear. B After inspection , replace front cover and tight en[...]

6 720 608 034 8 Installation instruction s 3.5 Combustion air requirements The BOSC H PRO wate r heater holds c old water in its copper heat exchanger and water valve when n ot i n use. Because of this, any c old air that comes down through the unit's vent p ipe is ca pable of free zing these components. Thi s Installation Manu al specifies th[...]

6 720 608 034 Installation instructio ns 9 3.6 Venting B Minimum vent p ipe diameter: 5 inches B Minimum vertic al vent heigh t: 6 feet, with no elbows B Establish 12 in ch rise before any elbow The heater must be vented to the outside follo wing all local ordinanc es and specificat ions for installing a gas appliance vent o r chimn ey. Th e heate [...]

6 720 608 034 10 Installation instruction s Masonry chim ney Masonry chimne ys s hall be built and installed in accordance with NFPS 211 or local codes. A minimum 5" diameter gas ven t pipe (metal doub le wall Type B), or an approved cl ay flu e liner or a listed chimney lining system must be used when v enting into a naturally drafting, inter[...]

6 720 608 034 Installation instructio ns 11 3.7 Gas piping & connections Before connecting the gas supply, chec k the ra ting plate on t he right s ide of the heater to be sure t hat the heater is rated for the same gas to which it will be connected. In the United States: The installation must conform with local cod es or, in th e absence of lo[...]

6 720 608 034 12 Installation instruction s FOR NA TU RAL GAS Maximum Cap acity of pipe in Cubic Feet o f Gas per Hour for Gas Pressu re of 0.5 Psig or le ss and a Pr essure drop of 0.3 in Wate r Column (0. 75mbar).(Ba sed on a 0.60 Spe cific Gravit y Gas) Btu nu mbers given in thousands. Cop per tubing is prohibited for use with Natural G as in th[...]

6 720 608 034 Installation instructio ns 13 3.8 Measuring gas pressure Connectin g manomet er B Shut off gas. B Remove f ront cover and locate inlet gas pres sure measuring poi nt on the right side, see Fig. 15. B Loosen screw from test point on the right sid e and connect manome ter tube on test point. Fig. 15 G as pressu re measuring point A Inle[...]

6 720 608 034 14 Operation i nstructions 3.10 Recirculation application Since recircu lation through the heater is not permissible, the following drawing is provided t o outline a p roper recirculation application using the B OSCH PRO water heat er with an Ariston minitank. This schematic is for illustrati on only and must not be used for actual in[...]

6 720 608 034 Operation in structions 15 4.2 Lighting instructions B STOP! Read t he previous safet y information. B The gas valve mus t be turne d off by sliding the gas valve button to a ll the way to the left. Fig. 18 B Wait five (5) min utes to clear ou t any g as. If y ou smell gas, STOP! Fo llow “B” in chapter 4.1. If you don’t smell ga[...]

6 720 608 034 16 Operation i nstructions 4.4 Setting the water temperature The GWH 425 P N h as a gas con trol t hat modulates burner input in respon se to flow. I ts purpose is to ensure that the hot water temperature will rem ain steady, a lthough the w ater flow demand might vary. The output temperature can be adjusted with eith er the temperatu[...]

6 720 608 034 Maintenance and service 17 5 Mainten ance a nd ser vice 5.1 Maintenance intervals The GWH 425 PN requires periodic maintenance. The below time ma intenance intervals shoul d kept the un it operating for many years . Every year B Inspect inlet w ater filter scr een ( 5.2) B Inspect pilot a ssembly and fl ame ( 5.3) B Inspect burne r as[...]

6 720 608 034 18 Maintenance and service 5.4 Main burners The ma in burner flame s s hould be blue, with a more intense blue c one in th e center core. Yello w flames could be a sign of wrong size gas orifices or dirty burners, a block age on the heat e xchangers fins. If some burners have yellow fla mes while others have blu e flames, it is li kel[...]

6 720 608 034 Troubleshooti ng 19 6 Troubles hootin g 6.1 Introduction Many of the questions customers ask regarding operation of this unit c an be a nswered by followi ng the troubleshoot ing ste ps a s outl ined below. Visit our web site at www.boschpro.c om for more detailed troubleshoot ing. For best results, p erform each step before proceedin[...]

6 720 608 034 20 Troubleshoot ing 6. Verify pilot fla me complete ly engulfs th e thermocoupl e tip. If pilot is too small, clean pilot orif ice (see chapter 5. 3). 7. If the w ater has a high mineral con tent, the heat exchanger may be scaled internally. T his restricts th e water pa th, cau sing the water t o over heat which shu ts all gas off to[...]

6 720 608 034 Troubleshooti ng 21 6.7 Water is too hot 1. Verif y gas type indicated in rating s ticker locate d on right-hand side of cover, coincides with t he gas t ype you are us ing. NG is a natural gas unit and L P is for liquid prop ane. 2. Adjust the ga s control slide b utton from three flame position towards the one flame position for coo[...]

6 720 608 034 22 Troubleshoot ing the way clockwise, the flow rate sho uld be clos e to 2gpm, filli ng the jug in 15 se conds. W ith the temperature adjustment kn ob set all the wa y counterclockwi se, th e flow rate should be close to 4gpm, fillin g the jug in 7 seconds. If the flow rate is not adequate, inspect and clean the inlet filt er scre en[...]

6 720 608 034 Protecting t he environme nt 23 7 Protectin g th e envir onmen t Packing The packing box may be fully recycled as confi rmed b y the recyclin g symbol . Componen ts Many parts in th e heater can be fully recycled in the end of the produ ct life. Contac t y our city authorit ies for information about the disp osal of recycl able produc[...]

6 720 608 034 24 Interior co mponents and diagram part s list 8 Interior comp onents and di agram parts list 8.1 I nterior components Fig. 28 F unctional s cheme 4 Heat e xchange r 5 Burner 10 Tempe rature adjustm ent sele ctor 11 Water valve 20 Gas con necti on 22 Flexib le hot o utlet 26 Gas con trol slide 30 Pilot g as tub ing 102 Piezo[...]

6 720 608 034 Interior compon ents and diagram part s list 25 8.2 Components diagram Fig. 29 C omponen ts Diagram 43 50 49 32 48 46 45 28 29 30 31 25 17 18 19 20 21 23 26 24 27 33 34 35 13 36 37 22 38 39 40 41 42 44 47 8 9 11 12 13 14 15 16 10 6 4 5 51 1 2 3 7 672 060 8126 -02.1 JF 52[...]

6 720 608 034 26 Interior co mponents and diagram part s list 8.3 Par ts list Item Description R eference 1 Front cover 8 705 431 246 0 2 Shield 8 705 506 817 0 3 Temp control kno b 8 702 000 295 0 4 Draft Diverter 8 705 505 442 0 5 Exhaust pipe u nion Ø128 8 705 504 046 0 6 Angle bracket 8 708 003 192 0 7 Trade mark badg e 8 701 103 135 0 8 Heat [...]

6 720 608 034 Fifteen Y ear Limited Wa rranty 27 9 Fifteen Year Li mited Warr anty General BOSCH PRO water heaters are warra nted by the Manufactu rer (B OSCH) through BBT North Ame rica. BBT North America (BBTNA) will furnish a rep lacement heat excha nger and w ill furnish a rep lacement of any other p art which fails in no rmal use a nd se rvice[...]

Recycled pa per © 200 6 B BT N O RTH AM E R IC A CO R P OR A TI O N , W aits field , VT all rights reser ved VU L CAN O T ermodomé sticos S.A . Estrada de Caci a 38 0 1 - 8 56 Aveiro - PO RTUGA L BBT NORTH AMERICA Bosch Group Bosch Water Heating 340 Mad River Park Waitsfield, VT 05673 Phone 866-330-2730 Fax 802-496-6924 www.boschpro.com techsuppo[...]