Bosch GWH 345 ESR, User Manual

Page 1: ...al For assistance or additional information consult a qualified installer service agency or the gas supplier In the Commonwealth of Massachusetts this product must be installed by a licensed plumber or gas fitter Upon completion of the installation these instructions should be handed to the user of the appliance for future reference What to do if you smell gas Close gas valve Open windows and door...

Page 2: ...ram and parts list 35 8 1 Interior components 35 8 2 Components diagram 36 8 3 Parts list 37 9 Protecting the environment 38 10 Ten Year Limited Warranty 39 1 Warning For your safety Do not store or use gasoline or other flammable combustible or corrosive vapors and liquids in the vicinity of this or any other appliance Warning Carefully plan where you install the heater Correct combustion air sup...

Page 3: ...nce received including interference that may cause undesired operation Fig 1 Warning The recirculating water heater must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0 5 psig 14 W C Caution Any changes or modifications not expressly approved by the party responsible for compliance could void the user s authorit...

Page 4: ...ency 82 GWH450 Combustion efficiency 81 Min Output GWH345 23 900 Btu h 7 kW GWH450 35 500 Btu h 10 4 kW Temperature Control Selection range 115 F 45 C 190 F 90 C Gas Requirement Gas connection inches Inlet gas pressure under operation with a high hot water flow rate Propane 11 14 water column Natural Gas 5 5 8 water column To measure gas pressure see Measuring Gas Pressure chapter 3 8 Venting 3 AL...

Page 5: ...n card Before installing the unit be certain you have the correct heater for your type of Gas Propane or Natural Gas Identification labels are found on the shipping box and on the rating plate which is located on the right side panel of the cover To remove front cover B Loosen the two Philips head screws located as shown in fig 2 Fig 2 Screws B Pull control panel outwards and then pull it downward...

Page 6: ...pplied with heater during any pressure testing at pressures in excess of Psig 3 5 kPa 6 Keep water heater area clear and free from combustibles and flammable liquids Do not locate the heater over any material which might burn 7 Correct gas pressure is critical for the optimum operation of this heater Gas piping must be sized to provide the required pressure at the maximum output of the heater whil...

Page 7: ...xhaust adapter with CO2 measuring point 3 Front cover 4 On Off button 5 Reset button 6 Recirculating water temperature selector 7 LED ON warning light blinks when in error lock out 8 Domestic hot water temperature selector 9 Mounting plate Fig 5 Minimum clearances Model GWH 345 450 ESR TOP 12 FRONT B 4 BACK 0 SIDES BOTTOM 12 Table 1 Minimum clearances ...

Page 8: ...taneous water heater direct tank load design Fig 6 Fig 7 Service position to access water and electric connections Caution the water heater which will be used to supply potable water shall not be connected to any heating system or component s previously used with a nonpotable water heating appliance Caution Do not overpump the heater Maximum 5 gpm water flow permitted through the heater Note maxim...

Page 9: ...ing a water condi tioner or softener GWH 345 ESR 0 feet of head 10 feet of head 20 feet of head 30 feet of head 40 feet of head 50 feet of head 0 GPM 1 GPM 2 GPM 3 GPM 4 GPM 5 GPM 6 GPM water flow rate Inlet pressure GWH 450 ESR 0 feet of head 10 feet of head 20 feet of head 30 feet of head 40 feet of head 50 feet of head 0 GPM 1 GPM 2 GPM 3 GPM 4 GPM 5 GPM 6 GPM water flow rate Inlet pressure Des...

Page 10: ... steel AL29 4C vent pipe rated for Category III appliances must be used when exhaust venting this appliance See 3 6 Venting 3 4 Mounting installation B Secure the wall mounting bracket provided with the heater to a wall surface If wall is a stud wall sheathed with plasterboard it is rec ommended that support board s either 1x4 s or 1 2 minimum plywood first be attached across a pair of studs Then ...

Page 11: ...quate combustion air for the recirculating water heater as well as any other appliances that may consume air in the space Always follow local codes if more stringent Appliances located in unconfined spaces a An unconfined space is one whose volume is greater than 50 cubic feet 1 42 cubic meter per 1000 Btu per hour 292 81 watts of the combined rating of all appliances installed in the space That w...

Page 12: ...orizontal ducts 4000 Btu hr 1171 24 watts if all air is taken from the outside by direct openings Or the confined space must be provided with one permanent opening or duct that is within 12 inches 304 8mm of the ceiling of the enclosure This opening must have a minimum free area of one square inch per 3000 Btu hr 878 43 watts if all air is taken from the outside by a direct opening Louvers grills ...

Page 13: ...last horizontal run including the termination must be sloped to the outside 1 4 per foot to prevent rain from entering the venting system Fig 12 Minimum exhaust vent length Danger Do not combination vent this appliance with any other appliance Warning Do not reduce the vent exhaust and combustion pipe sizes Warning Failure to vent the exhaust gases to the outside with sealed stainless steel vent p...

Page 14: ... the top of the unit position 1 using the 4 screws and gasket provided B Insert 3 single wall stainless steel vent pipe into exhaust vent adapter 1 5 and tighten the clamp position 2 Note Failure to fully insert and tighten vent pipe may cause flue gas leakage or condensate damage that is not covered under the manufacturer s warranty Company Contact information Z flex www z flex com 800 654 5600 P...

Page 15: ...6 720 607 909 Installation instructions 15 Fig 14 Exhaust vent connection ...

Page 16: ...GWH 450 ESR termination Intake 5 4 straight sections 2 1 straight sections Total length 22 2 90 elbows 1 GWH 450 ESR termination Example Using table 8 the following restrictors would be required GWH 450 ESR NG restrictor 55 GWH 450 ESR LP restrictor 55 Exhaust 1 Straight section length __ x 1 ____ 2 90 elbows qty __ x 6 ____ 3 45 elbows qty __ x 3 ____ 4 GWH 345 ESR termination __ x 15 ____ 5 GWH ...

Page 17: ... deflector gasket and inlet air restrictor on the air inlet opening lining up screw holes as seen in Fig 15 Fig 15 Mounting sequence a Gasket b Deflector c Restrictor d Adaptor B Attach the combustion air inlet accessory 8 705 504 141 to the top of the unit position 3 using the 4 screws provided B Install 3 combustion air pipe over the air inlet accessory If using flexible piping secure with a cla...

Page 18: ...high temperature silicone tubing with vinyl tubing PVC or CPVC pipe Do not reduce the internal diameter at any point Fig 17 Required condensate drain installation 3 6 4 Room sealed installation Twin pipe Although it is permitted to draw combustion air from inside the recommended method is to provide combustion air through a 3 pipe from the outside See Chapter 3 5 for more direction on combustion a...

Page 19: ...op of the chimney must be sealed to prevent rain water or other elements from entering the chimney Exterior Masonry Chimney Refer to the National Fuel Gas Code and consult a local venting HVAC contractor Not recommended in cold climates 3 6 6 Horizontal terminations An approved vent terminator must be used See Table 5 for known approved horizontal vent terminations Install a condensate drain if th...

Page 20: ...erior of the building at a minimum height of eight 8 feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or equipment The sign shall read in print size no less than one half 1 2 inch in size GAS VENT DIRECTLY BELOW KEEP CLEAR OF ALL OBSTRUCTIONS 4 INSPECTION The state or local gas inspector of the side wall horizontally vented g...

Page 21: ... Below a gutter sanitary pipework or eaves protected by metal shielding 12 in C From any internal corner 12 in D Above ground or snow pack 12 in Above a paved sidewalk 7 ft E From an opposing wall or structure facing the termination 24 in From the relief valve of a Ip gas regulator 36 in F From a terminator facing a terminator 48 in G Vertically between two exhaust vent terminators on the same wal...

Page 22: ...de wall venting installation Fig 23 Vertical venting installation Masonry Chimney Fig 24 Vertical venting installation NOTE If appliance uses room air do not place any other combustion appliance in the same space to avoid depressurizing of the building and winter freeze up Use room sealed operation instead ...

Page 23: ...ed to detect for leaks GAS LINE SIZING The gas supply piping should be sized according to the applicable code for a maximum draw of 120 000 BTUH GWH450ESR or 96 000BTUH GWH345ESR Measure the length of gas supply line and use the tables in Fig 26 or the gas line manufacturer s sizing tables to determine the pipe diameter necessary to accommodate the BTU demand of the unit If there are more gas draw...

Page 24: ...2 18 15 14 12 11 11 10 9 8 8 7 6 3 8 0 493 72 49 40 34 30 27 25 23 22 21 18 17 15 14 1 2 0 622 132 92 73 63 56 50 46 43 40 38 34 31 28 26 3 4 0 824 278 190 152 130 115 105 96 90 84 79 72 64 59 55 1 1 049 520 350 285 245 215 195 180 170 160 150 130 120 110 100 1 1 4 1 380 1050 730 590 500 440 400 370 350 320 305 275 250 225 210 1 1 2 1 610 1600 1100 890 760 670 610 560 530 490 460 410 380 350 320 2...

Page 25: ...W C for nat ural gas or 11 W C for LP will result in improper oper ation and must be corrected See Chapter 3 7 for gas line sizing requirements 3 9 Checking restrictor plate size by measuring CO2 level value B Remove brass flat head screw on the exhaust collar Fig 28 Measuring port B Insert CO2 analyzer probe into the measuring point The tip of the probe should be in the center of the flue pipe Av...

Page 26: ...rt in the piping Blow out or flush the lines before connecting to the water heater B Full port shut off valves should be installed on both the cold water supply and hot water outlet lines to facilitate servicing the heater see Fig 30 Connecting the pressure relief valve PRV The listed pressure relief valve supplied with the heater must be installed at the time of installation No valve is to be pla...

Page 27: ...Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been under water 4 3 Startup instructions B 1 STOP Read the previous safety information B 2 The gas valve must be shut off by putting the ON OFF switch to position OFF Wait five 5 minutes to clear out any gas If you smell gas STOP Follow the safety in...

Page 28: ...t control left knob should be in maximum position To activate and use the appliance domestic temperature dial a 12 kOhm thermistor is required part number 8 714 500 034 See 2 6 Page 8 for wiring diagram B Connect the 12kOhm thermistor blue wire to the DHW NTC terminal block Install the sensor in the tank well Hot water temperature can be set from 50 F to 158 F using hot water temperature selector ...

Page 29: ...lve 13 Junction box wiring of tank pump 14 Fan 15 Temperature limiter ECO 16 Differential pressure switch 17 TT connection under low voltage cover plastic 18 Domestic hot water temperature sensor 12kOhm only under low voltage cover plastic 19 LED 20 Fuse NOTICE Except for the fuse there are no serviceable parts inside the electronics ...

Page 30: ...e heat exchanger thoroughly and repeat annually depending on mineral content of ground water 5 1 Service mode The service mode provides diagnostic information to the technician with a variety of real time parameters See Table 15 for the parameters and their respective meaning Accessing the service mode B Switch on the equipment B Press and hold the reset button B Rotate the hot water temperature s...

Page 31: ...2kOhm external thermistor 07 Selected DHW temperature only if 12kOhm thermistor used Displays the hot water temperature as selected by the user during non diagnostic mode operation only if 12kOhm external thermistor used 08 Not used 09 Pressure switch 00 Open pressure switch fan is off or there is no exhaust gas flow 01 Closed pressure switch fan is on or there is exhaust gas flow 10 Temperature l...

Page 32: ...s and wiring 2 Replace electronic unit C4 Fan not working 1 No power to fan check for 115 volts at fan 2 Check wire connections C6 Shut down by pressure switch 1 Blocked vent 2 Fresh air supply inadequate 3 Silicone tubes from pressure switch not connected clear or clear and black 4 Check wire and connection E2 Heating NTC defect no function 1 Check heating NTC 2 Check cable opened short 3 Check e...

Page 33: ...ng no tank load function No heat demand by the NTC defect 1 Check NTC cable 2 Check water filter 3 Check Domestic hot water NTC Tank 4 Check electronic unit1 Low temperature domestic hot water To low burner power burner ON OFF 1 Check air vent 2 Check Adjustment of gas gas valve 3 Check Domestic hot water NTC 4 Check electronic unit1 Insufficient water flow Low water pressure Filter taps or heat e...

Page 34: ...6 720 607 909 34 GWH 345 450 ESR Functional scheme 7 GWH 345 450 ESR Functional scheme Fig 36 Functional scheme APS Air Pressure Switch ...

Page 35: ...right side only 2 Exhaust adapter with CO2 measuring point 3 Front cover 4 On Off button 5 Reset button 6 Recirculation water temperature selector 7 LED ON warning light blinks when in lock out 8 Domestic hot water temperature selector 12 Gas valve 20 Junction box 21 Centrifugal blower 22 Main burner 23 Heat exchanger 24 Holding bracket 25 Outlet water pipe 26 Inlet water pipe ...

Page 36: ...6 720 607 909 36 Interior components diagram and parts list 8 2 Components diagram Fig 38 Components Diagram ...

Page 37: ...9 158 12 Screw 8 743 401 019 13 Cage nut 8 703 309 001 14 Screw M 5 0X20 DIN 7985 2 910 642 162 15 Clip 8 716 102 607 GROUP 3 1 Main burner LP GWH345ESR 8 708 120 625 1 Main burner NG GWH345ESR 8 708 120 624 1 Main burner LP GWH450ESR 8 708 120 623 1 Main burner NG GWH450ESR 8 708 120 622 Table 17 2 Screw 8 703 404 089 3 Screw 8 703 401 069 4 Screw M4 x 12 phillips 2 910 952 122 9 Washer 8 701 003...

Page 38: ...y authorities for information about the disposal of recyclable products Saving water resources B Make sure you close all the taps after any use Avoid leaving the taps dripping Repair any leaking tap B Whenever possible use taps with built in water flow limiters They will give you the same comfort level while saving water B Set the water temperature to the desired temperature or slightly higher Hot...

Page 39: ... and or highly mineralized unsoftened water supply All Other Parts If any other part fails within one 1 year after original installation and operation Bosch Thermotechnology Corp will furnish a replacement part free of charge Service Labor Costs This warranty does not cover any labor costs associated with service removal or re installation of part s All such costs must be borne by the Purchaser Ad...

Page 40: ...e on right side panel Gas Pressure reading Static__________ Operating__________ CO2 reading __________ Air restrictor size __________ Building Water Pressure __________ Range if on Well system __________ Installing Company _____________________________________________ Installer name _____________________________________________ Address _____________________________________________ Phone __________...