GWH 345/450 ESR Temperature Modulated with Electronic Ignition Suitable for heating and recirculating potable water 6 720 607 909 US (2008.02) JS GWH-345/450-ESR-N - Natural Gas GWH-345/450-ESR-L - Liquefied Petroleum (LP) Gas 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.
Index Index 1 Warning 2 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Appliance details Features GWH-345/450-ESR Specifications (Technical data) Unpacking the GWH-345/450-ESR heater General rules to follow for safe operation Dimensions and minimum installation clearances Applications Water quality 4 4 4 5 6 7 8 9 3 3.1 3.2 3.3 3.4 3.5 3.6 3.6.1 3.6.2 3.6.3 3.6.4 3.6.5 3.6.6 3.6.7 3.7 3.8 3.9 3.10 3.
Warning 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.). FCC: This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
Appliance details 2 Appliance details 2.1 Features Temperature Control Selection range: 115°F (45°C) - 190°F (90°C) Parts • Sealed combustion burner. Gas Requirement Safety Gas connection (inches) - ¾” • Ionization flame sensor Inlet gas pressure under operation (with a high hot water flow rate)* • Over temperature protection. High quality materials for long working life • Copper heat exchanger • Compact space saver: mounts on a wall with supplied bracket.
Appliance details Water resistant IP X4 (protection against water drops) 2.3 Unpacking the GWH-345/450-ESR heater This heater is packed securely. The box includes: To remove front cover i The front cover is secured with two screws to prevent unauthorized access. Always secure the control panel and front cover with these screws. B Loosen the two Philips head screws located as shown in fig. 2.
Appliance details 2.4 General rules to follow for safe operation 1. You must follow these instructions when you install your heater. In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54. In Canada: The Installation must conform with CGA B149.(1,2) INSTALLATION CODES and /or local installation codes. 2. Carefully plan where you install the heater.
Appliance details 2.5 Dimensions and minimum installation clearances Fig. 4 Dimensions 1 2 3 4 5 6 7 8 9 Combustion air inlet adapter (right side only) Exhaust adapter with CO2 measuring point Front cover On/Off button Reset button Recirculating water temperature selector LED - (ON) warning light (blinks when in error lock out) Domestic hot water temperature selector Mounting plate Fig.
Appliance details 2.6 Applications 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. Introduction The application designs provided in this manual are general guides to be used when installing this recirculating water heater. Pump Sizing Required PS pumps are Taco 007 Bronze or Grundfos 15-42B.
Appliance details Pressure drop curves Note: Flow above 6 GPM is not permitted. 50 feet of head GWH 345 ESR Inlet pressure 40 feet of head 30 feet of head 20 feet of head 10 feet of head 0 feet of head 0 GPM 1 GPM 2 GPM 3 GPM 4 GPM 5 GPM 6 GPM 5 GPM 6 GPM water flow rate Fig. 8 GWH 345 ESR 50 feet of head GWH 450 ESR Inlet pressure 40 feet of head 30 feet of head 20 feet of head 10 feet of head 0 feet of head 0 GPM 1 GPM 2 GPM 3 GPM 4 GPM water flow rate Fig. 9 GWH 450 ESR 2.
Installation instructions 3 Installation instructions 3.1 Introduction Please follow these instructions. Failure to follow instructions may result in: • Property damage or personal injury • Improper operation • Heater damage • Loss of warranty. Please contact Bosch Water Heating with any questions. 3.2 Proper location for installing your heater Carefully select the location of the water heater.
Installation instructions Single pipe Although it is permissible to draw combustion air from inside the structure, it is not the manufacturer’s recommended installation method. Always install a 3 inch elbow on the combustion air inlet to prevent foreign objects from falling into the unit (see Fig. 11). Fig. 11 Fig. 10 Mounting the heater 3.5 Combustion air requirements Warning: In areas where freezing temperatures are common the twin pipe system is recommended.
Installation instructions • Appliances located in confined spaces: The confined space must be provided with two permanent openings, one commencing within 12 inches (304.8mm) of the top and one commencing within 12 inches (304.8mm) of the bottom of the enclosure. Each opening must have a minimum free area of one square inch per: – 1000 Btu/hr (292.81 watts) if all air is taken from inside the building – 2000 Btu/hr (585.62 watts) if all air is taken from the outside by horizontal ducts – 4000 Btu/hr (1171.
Installation instructions 3.6 Venting 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 pipe (AL29-4C) may result in dangerous flue gases filling the structure in which it is installed. Warning: Do not mix vent pipe or joining methods from different manufacturers.
Installation instructions Z flex Protech Heat Fab TEE only TEE only 9390 TEE 2SVSRCF03 FSRC3 5300CI 90° Condensate drain Tee 2SVEVWCF03 FST3 & FSDF3 93PLSTEE Horizontal Condensate drain 2SVEDWCF03 FSHD03 9321 Vertical Condensate drain 2SVSEVDP03 N/A N/A Condensate Drain Tube 2SVEDTK N/A 7000TUBE 3” Horizontal terminator Vent pipe 3” Vertical terminator Reduce maximum length 6 ft for each 90 elbow after the first one and 3 ft for each 45 elbow. Combustion air intake Fig.
Installation instructions Fig.
Installation instructions Selecting inlet air restrictor Example Note: Before installing the combustion air inlet accessory, the appropriate inlet air restrictor must be determined using Tables 6, 7 and 8. Refer to Fig. 15 for mounting sequence. Exhaust • 10 - 3' straight sections • 1 - 1' straight section Total length 31' B Determine the total length of the straight sections of 3" stainless steel exhaust and enter that length in line 1.
Installation instructions Restrictor Ø 20 - 38 38 38 - 78 40 18 - 28 44 28 - 40 47 40 - 65 50 65 - 78 55 Total equivalent length (ft) Restrictor Ø GWH345 LPG 20 - 38 38 38 - 78 40 18 - 28 47 28 - 50 50 50 - 78 55 GWH450 NG GWH345 NG Total equivalent length (ft) GWH450 LPG Use table below to define which restrictor to be used. Combustion air inlet connection The combustion air inlet accessory can only be connected to the top right of the appliance.
Installation instructions 3.6.3 Condensate drain requirements An external condensate drain must always be installed except when using one 90° elbow and less than 3 feet of horizontal pipe. Note: condensate must be disposed of according to local codes. 1. Install condensate drain as close to heater as possible. 2. Use 3/8" ID high temperature silicone tube to connect to condensate drain port. Do not use copper piping for any portion of the condensate drain. 3.
Installation instructions 3.6.5 Vertical terminations Caution: Failure to install a condensate drain may result in damage not covered by the manufacturer's warranty. See chapter 3.6.3. An approved vent terminator must be used. See Table 5 for known approved vertical vent terminations. Over 12/12 to 14/12 5.0 1.52 Over 14/12 to 16/12 6.0 1.83 Over 16/12 to 18/12 7.0 2.13 Over 18/12 to 20/12 7.5 2.27 Over 20/12 to 21/12 8.0 2.
Installation instructions 3.6.6.
Installation instructions Recommended exhaust vent terminator position Fig. 21 Ref.
Installation instructions 3.6.7 Exhaust vent configuration examples Fig. 22 Horizontal side wall venting installation 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. Fig.
Installation instructions 3.7 Gas piping & connections Before connecting the gas supply, check the rating plate on the right side of the heater to be sure that the heater is rated for the same gas to which it will be connected. In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54. In Canada: The installation must conform to CGA B149 INSTALLATION CODES and/or local installation codes.
Installation instructions FOR NATURAL GAS Maximum Capacity of pipe in Cubic Feet of Gas per Hour for Gas Pressure of 0.5 Psig or less and a Pressure drop of 0.3 in Water Column (0.75mbar).(Based on a 0.60 Specific Gravity Gas) Btu numbers given in thousands. Follow boxed numbers for piping just one GWH-450-ESR (example: ¾” B.I. Natural Gas pipe for 20 ft (6.1m). will handle 190,000 btu’s (55.7 kWh). For multiple appliances combine the total btu input load and then refer to applicable chart below.
Installation instructions 3.8 Measuring gas pressure Static Gas Pressure Reading (see Chapter 3.8) Connecting manometer B Turn power off. enter here: ___________________ B Shut off gas supply. Operating Gas Pressure Reading (see Chapter 3.8) B Remove front cover and locate the inlet gas measuring point (see Fig. 27). enter here: ___________________ B Loosen screw inside test point fitting (do not remove) and connect manometer tube on test point. Table 11 3.
Installation instructions B If the CO2 content is too high, use the next smallest restrictor. piping. Blow out or flush the lines before connecting to the water heater. B After replacing the restrictor, measure CO2 level again. Repeat procedure until correct level is obtained. 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).
Operating instructions 4 Operating instructions 4.1 Initial filling instructions Before proceeding with the operation of the heater make sure that the system is filled with water: B Turn off power supply to heater. B Open the cold water inlet supply to the heater fully. B Open a hot water faucet to permit the water to fill the heater and the piping and to eliminate the air trapped in the system. B Close the hot water faucet after the water flows freely and all the air has escaped from the system.
Operating instructions 4.4 Power 4.6 Temperature and hot water flow On Choose one the following: To start the appliance: • If using a tank mounted Aquastat, set temperature on Aquastat control (left knob should be in maximum position). B press the ON/OFF button. LED (fig. 31) goes orange. When the burner is working, the LCD display shows the symbol . • To activate and use the appliance domestic temperature dial, a 12 kOhm thermistor is required (part number 8 714 500 034) (See 2.
Operating instructions 4.8 Electrical diagram Fig. 35 Electrical scheme 10 11 12 13 14 15 16 17 Flame sensor Ignitor electrode Gas valve Junction box (wiring of tank pump) Fan Temperature limiter / ECO Differential pressure switch TT connection - under low voltage cover plastic 6 720 607 909 18 19 20 Domestic hot water temperature sensor (12kOhm only under low voltage cover plastic) LED Fuse NOTICE: Except for the fuse, there are no serviceable parts inside the electronics.
Maintenance and service 5 Maintenance and service Adjusting parameters Warning: Always turn off the electrical power supply, turn off the manual gas valve and turn off the manual water shut off valves whenever servicing. B Rotate hot water temperature selector dial to change the value of the parameter (only parameter 03 and 22). The unit should be checked once a year by a gas technician.
Maintenance and service Mode Parameter Values 01 Not used ---------- 02 Not used ---------- 03 Error code history Displays the last 8 error codes. Use the hot water temperature selector (right dial) to toggle from newest (left) to oldest (right) error codes. 04 Actual primary circuit temperature Displays the actual temperature in the primary circuit as detected by the internal heating circuit sensor.
Troubleshooting 6 Troubleshooting Fault Indication Possible Cause Check E9 Shut down by the temperature limiter (over temperature). • 1. Check position of heating NTC • 2. Check temperature limiter, cables • 3. Check system with air, air vent • 4. Bleed air from system. EA No Flame detected (no ignition). • 1. Check gas inlet pressure, gas type, air inside gas pipe • 2. Check flame, ignition • 3. Check burner pressure, injectors • 4. Check ionisation sensor, cable • 5. Check electronic unit1).
Troubleshooting Fault Indication Possible Cause Check Only tank loading (no heating function). No heat demand by the thermostat, thermostat not well adjusted, other defect. • 1. Check thermostat position No heat demand by the NTC, defect. • 1. Check NTC cable Only heating (no tank load function). • 2. Check electronic unit1). • 2. Check water (filter, …) • 3. Check Domestic hot water - NTC (Tank) • 4. Check electronic unit1). Low temperature (domestic hot water).
GWH-345/450-ESR Functional scheme 7 GWH-345/450-ESR Functional scheme APS - Air Pressure Switch Fig.
Interior components diagram and parts list 8 Interior components diagram and parts list 8.1 Interior components Fig.
Interior components diagram and parts list 8.2 Components diagram Fig.
Interior components diagram and parts list 8.3 Item Parts list Description Reference GROUP 1 Item Description Reference 2 Screw 8 703 404 089 3 Screw 8 703 401 069 4 Screw M4 x 12 phillips 2 910 952 122 9 Washer 8 701 003 010 10 Angle bracket 8 711 304 287 11 Screw 2 910 619 409 12 Washer 1" 8 710 103 060 13 Ignition electrode 8 708 107 008 14 Screw m3.5x6 phillips steel 2 910 642 082 15 Flame sensor 8 708 107 009 1 Front cover 8 705 431 223 2 Cover screw no.
Protecting the environment 9 Protecting the environment Packing The packing box may be fully recycled as confirmed by the recycling symbol . Components Many parts in the heater can be fully recycled in the end of the product life. Contact your city 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.
Ten Year Limited Warranty 10 Ten Year Limited Warranty General BOSCH PRO water heaters are warranted by the Manufacturer. Bosch Thermotechnology Corp. will furnish a replacement heat exchanger and will furnish a replacement of any part which fails in normal use and service within the applicable periods specified below, in accordance with the terms of this warranty. The replacement will be warranted for the unexpired portion of the original warranty.
Installer Checklist, to be performed by installer upon installation Serial Number ___ ___ ___ ___ ___ ___ ___ ___ (8 digit serial number is located on rating plate 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 _____________________________________________ Add
