MODEL GWH 2700 ES NG and GWH 2700 ES LP INDOOR MODEL Temperature Modulated with Electronic Ignition Suitable for heating potable water only Not approved for space heating purposes (Intended for variable flow applications) GWH 2700 ES NG - Natural Gas GWH 2700 ES LP - Liquefied Petroleum (LP) Gas 6 720 608 542 (2008/10) US Warning: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death.
Index Index 1 Warning 3 2 2.1 2.
Warning 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 supply and flue pipe installation are very important. If a gas appliance is not installed correctly, fatal accidents can result, such as carbon monoxide poisoning or fire.
Appliance details Warning: If a relief valve discharges periodically, this may be due to thermal expansion in a closed water supply system. Contact the water supplier or local plumbing inspector on how to correct this situation. Do not plug the relief valve. FCC: This device complies with Part 15 of the FCC rules.
Appliance details 2.2 GWH 2700 ES Specifications (Technical data) Approved in US/Canada Capacity Maximum flow rate: 7.15 GPM (27 l/min) at a 45°F (25°C) rise. Maximum output 160,500 Btu/h (47.0 kW) Maximum input 199,000 Btu/h (58.3 kW) Efficiency in % Thermal efficiency > 82% Min. Input 19,900 Btu/h (5.
Appliance details 2.3 Unpacking the GWH 2700 ES heater 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 on bottom rear of cover (see Fig. 3). Fig. 3 Loosen the two screws B Lift front cover panel upward and remove. Fig.
Appliance details 2.4 General rules to follow for safe operation B 10. Failure to install heater correctly may lead to unsafe operation and void the warranty. B 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. B 2.
Appliance details 2.5 Fig. 6 1 2 3 4 5 6 7 Dimensions and Minimum installation clearances Dimensions On/Off button Reset button Program key Power ON or stand-by LED LCD display Up button Down button Model GWH 2700 ES TOP (A) 12” FRONT (B) 1” BACK 0” SIDES 1” FLOOR (C) 12” Table 1 Minimum clearances Fig. 7 Minimum clearances Note: For servicing access, a 2ft clearance to front cover is recommended.
Installation instructions 3 Installation instructions 3.1 Tools required for installation Warning: Proper end terminal / rain cap must be used. Failure to do so may result in damage to the appliance. This damage is not covered under the manufacturer's warranty. • Philips head screwdriver • Flat head screwdriver • Adjustable wrench • Level • Thermometer Caution: The vent system must be installed by a qualified installer in accordance with these instructions.
Installation instructions used. Horizontal sections of vent must pitch upwards towards termination ¼" for every foot of horizontal length, to prevent the pooling of condensate, and be supported at 4 foot intervals with overhead hangers. Exception: horizontal run between last elbow and termination must pitch down to termination 1/4" per foot. Note: For horizontal terminations, venting must terminate once it penetrates to the outside of the structure.
Installation instructions Recommended exhaust vent terminator position Fig. 10 Ref.
Installation instructions d Fixe ed Clos Q 6720608836-18.1JF Fig.
Installation instructions Venting configuration examples Fig. 14 Above the roof clearance requirements from rain cap (combustion air piping not shown) Fig. 12 Horizontal side wall venting installation (combustion air piping not shown) Important: Note: Pitch horizontal runs down toward the heater, except horizontal run between last elbow and termination which must slope down to termination 1/4" per foot.
Installation instructions 3.3.2 Condensate drain requirements Room sealed installation (TWIN PIPE SYSTEM) A condensate drain must be installed under the following conditions: • All vertical terminating vent installations • Horizontal terminating vent installations where the total equivalent exhaust vent length is greater than 10 feet. See table 9, page 17. Installing this water heater as a room sealed (TWIN PIPE SYSTEM) is the recommended method.
Installation instructions 3.3.3 Warning: Approved terminators must be used for inlet and exhaust vent systems to prevent rain from entering the appliance, failure to do so may result in damage to the appliance. This failure is not covered under the manufacturer’s warranty. Vent connections B Attach the flue gas exhaust accessory (8 705 504 151) to the top of the unit (position 1) using the 4 screws and gasket provided. Fully insert stainless steel vent pipe 1.
Installation instructions Attention residents of the Commonwealth of Massachusetts: signage installed in accordance with the provisions of 248 CMR 5.08(2)(a)1 through 4. In the Commonwealth of Massachusetts the following regulation went into effect on 12/30/2005: (b) EXEMPTIONS: The following equipment is exempt from 248 CMR 5.
Installation instructions 3.3.4 • 1 - 1' straight section = Total straight pipe length 22’ Fan speed adjustment IMPORTANT! Installation adjustment: • 2 - 90° elbow. After installing the GWH 2700 ES, the fan speed values for minimum power (P2) and maximum power (P1) may need adjustment due to variations in altitude and vent pipe length. Failure to make necessary adjustments to fan speed values may result in improper operation of the appliance. Intake First calculate the total equivalent vent length.
Installation instructions Altitude (above sea level) Vent terminal 0 - 2000 ft (0 - 610 m) Twin system 2000 - 4500 ft (610 - 1372 m) Twin system 4500 - 8000 ft (1372 - 2439 m) Twin system Total Minimum equivalent power fan vent length1) speed (P2) Natural Gas Liquid propane Maximum power fan speed (P1) Maximum power fan speed (P1) No modification required No modification required 3 - 32 ft 6 33 - 52 ft 7 3 - 32 ft 7* 45* 42* 33 - 52 ft 7* 46* 42* 3 - 32 ft 8* 46* 33 - 52 ft 8
Installation instructions 3.4 Combustion air requirements Warning: In areas where outside temperatures routinely come close to freezing, sealed combustion operation is required. Use separate terminations for combustion and vent, which must be installed on the same wall or roof surface, however never facing the direction of prevailing winds. Failure to do so may result in heat exchanger freezing up and bursting. This failure is not covered under the manufacturer's warranty.
Installation instructions 3.5 Proper location for installing your heater 3.7 Warning: before starting installation Carefully select the location of the water heater. For your safety and for proper heater operation, you must provide combustion air to the heater and a proper exhaust vent system. Follow the guidelines below: B Check that there are no loose or damaged parts inside the appliance B Confirm the gas type of the heater matches the gas supply you will be connecting the heater, see Fig.
Installation instructions 3.8 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 CSA B149 INSTALLATION CODES and/or local installation codes.
Installation instructions Once connections are made, check for gas leaks at all joints. Apply some gas leak detection solution to all gas fittings. Bubbles are a sign of a leak. A combustible gas detector may also be used to detect for leaks. Danger: If you have a leak, shut off the gas. Tighten appropriate fittings to stop leak. Turn the gas on and check again with a gas leak detection solution. Never test for gas leaks using a match or flame.
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 2700 ES (example: ¾” B.I. Natural Gas pipe for 10 ft (3.0m). will handle 278,000 btu’s (81.5 kWh). For multiple appliances combine the total maximum btu input load and then refer to applicable chart below.
Installation instructions 3.9 Water connections Warning: This heater is not approved for preheated water applications. See chapter 3.11 for approved recirculating application. B When facing the heater, the ¾” cold connection is on the bottom right and the hot connection is on the bottom left. Centrally locating the water heater is recommended to keep hot water distribution times even throughout the structure. 3.
Installation instructions the pump is commonly done. Contact Bosch Water Heating if further information is needed. 3.12 Measuring gas pressure Confirm gas pressure upon installation. Connecting manometer B Shut off gas supply at installer supplied shutoff valve for this water heater. B Remove front cover and locate inlet gas pressure measuring point (see Fig. 35). B Loosen screw inside left test point fitting (do not remove) and connect manometer tube to test point.
Installation instructions B Operate all other gas appliances on the same gas piping system at maximum output. B Record lowest operating gas pressure reading in table 14. Gas pressures lower than 3.5" W.C. for Natural Gas or 8" W.C. for LPG will result in insufficient degree rise to the hot water being used, reduced hot water volume, possible error code faults and must be corrected. See Gas Connections, chapter 3.8, page 21. Fig.
Electrical connections 4 Electrical connections 4.1 Electrical power supply Warning: For safety reasons, disconnect the power supply cord 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.
Operation instructions 5 Operation instructions Fig. 39 1 2 3 4 5 6 7 5.1 On/Off button Reset button Program Key LCD display Up button Down button LED - Power On indicator or Stand-by LCD Display functions Warning: Do not use any cleaning or corrosive agent to clean the window. Fig. 43 Lock indicator Fig. 44 Flame indicator Fig. 40 Power bar indicator Fig. 45 Remote control Fig. 41 Temperature indicator Fig.
Operation instructions 5.2 For your safety read before operating your water heater Warning: If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal injury or loss of life. 5.4 Temperature selection To select output water temperature: B Press buttons temperature. or in order to reach desired A. This appliance is equipped with electronic ignition for lighting the main burner. When turning the heater on, follow these instructions exactly. B.
Operation instructions 5.5 Use of optional remote control accessory (part no. TSTAT2) Fig. 51 Reset button If the problem persists, contact your installer. 5.8 Program button can be used on the appliance and in the remote control. Fig. 48 Remote control The wireless remote control accessory (Fig. 72, component 13) and the temperature selector buttons on the front of the water heater operate identically. Contact your distributor to order the remote control accessory.
Maintenance and service 6 Maintenance and service Warning: Always turn off the electrical power supply, turn off the manual gas shut off valve and turn off the water shut off valves whenever servicing. Caution: B Check and clean the complete water heating system once a year. Inlet water filter • Verify the inlet filter screen is clean and undamaged. The inlet water filter is located inside the cold water inlet fitting on the right side of the appliance (See Fig. 54, page 31).
Maintenance and service such as anti-freeze is not permitted as they may cause damage to the water heater's internal components. 1. Press ON/OFF switch on the water heater to turn OFF the heater and unplug power supply cord. The display should be blank. 2. Shut off gas supply to heater. 3. Shut off the water supply to the water heater using installer supplied shutoff valve. 4. Open hot water taps to drain the plumbing system.
Maintenance and service adjusting CO2 until pressure is at or above these levels, but not to exceed 10.5” WC for Natural Gas and 13” WC for Propane. P2 CO2 Reading: % CO2 P1 CO2 Reading: % CO2 A. Once Gas Pressure is adequate B Press ON/OFF button to turn off the heater. B Remove brass flat head screw on the exhaust collar as seen in Fig. 56. B Insert CO2 analyzer probe into the measuring port. The tip of the probe should be in the center of the flue pipe (approx 1.5" inserted).
Maintenance and service CO2 range (%) Max. CO level (measured) Nat. Gas max. input P1 7.0 % - 7.6 % < 250 ppm min. input P2 2.3 % - 2.6 % < 60 ppm LP Gas max. input P1 8.3 % - 8.9 % < 250 ppm min. input P2 2.5 % - 2.8 % < 60 ppm * Values above are for climate controlled conditions. Inputs such as gas pressure, heating value of the gas, humidity and temperature of combustion air all impact CO and CO2 values.
Maintenance and service 6.5 Program values This section describes details on programming the appliance. For most applications the factory default values will robust and stable operation. Only adjust the factory settings if the installation requires changes as indicated in the appropriate section of this manual. Refer to chapter 6.6 Control board diagnostics (page 36) regarding how to access these P-modes. Caution: Misadjusted program values can lead to appliance malfunction, errors, and service calls.
Maintenance and service 6.6 Control board diagnostics 1. Turn on/off switch on water heater to off (O) position. 2. Press and hold the program ( ) button while turning the on/off switch to the on (I) position. The display will cycle through a startup procedure including the software version. 3. Release the ' ' button when '188' appears on the display. The display should read 'P2' when the program button is released. If not, repeat process.
Troubleshooting 7 Troubleshooting Warning: If you are unable to perform the tasks listed below, or need additional assistance please contact your original installer or licensed gas technician. 7.1 Introduction Many of the questions customers ask regarding operation of this unit can be answered by following the troubleshooting steps as outlined below. Visit our web site at www.boschhotwater.com for more detailed troubleshooting and service bulletins.
Troubleshooting heater. Then open all of the hot water taps served by the heater. Wait 10 minutes and check all taps for water flow. There should be no water flowing. Any continuous flow of water, small or large, indicates a crossover and must be corrected. Consult a professional plumber for help in correcting a crossover. Failing single lever faucets and mixing valves are common causes of plumbing crossovers. 8.
Troubleshooting 5. Lack of adequate gas pressure. Inadequate gas pressure will cause the fuel-to-air mixture (CO2) to be out of adjustment. This will result in unstable burner flames and noise. Ensure gas pressure is in accordance with specifications in section 3.12, page 25 Measuring Gas Pressure. A gas pressure reading is needed to proceed further. Contact your original installer or a local certified gas technician to obtain this reading. 6. Verify proper CO2 readings per chapter 6.4, page 32.
Problem solving 8 Problem solving 8.1 Error code diagnostics i To remove error code from the display, press the reset button. Display Cause Solution Fault in the flue gas limiter. 1. Check continuity of the flue gas limiter (see Fig. 65, page 48). Go to steps two and three to determine air box temperature sensor fault and replace it. 2. Check for flue gas leakage around the top and bottom seals of heat exchanger as well as the viewing window. 3.
Problem solving Display (Flashing) (Flashing) Cause Solution Outlet temperature sensor not sensing expected output temperature. 1. Check that the sensor is firmly attached to the hot water pipe (see Fig. 71, page 54). 2. Clean inlet filter screen and clear any debris out of shower heads, faucet aerators and whole house filters. 3. Check venting specifications are met. Long vent lengths, venting with more than three elbows, blocked vent or combination venting may cause this failure. 4.
Problem solving Display Cause Solution Over-temperature detected by outlet temperature sensor on hot water pipe. Temperature > 185°F 1. Check that the sensor is firmly attached to the vertical section of the hot water pipe (see Fig. 71, page 54). 2. Check red wire connections at outlet temperature sensor. Clean terminals with an eraser. If badly corroded, replace sensor and wire harness. Check sensor resistance (see Fig. 61, page 45. 3. Clean inlet filter screen per chapter 6.
Problem solving Display Cause Solution No flame ionization detected with water flow. 1. Verify that all manual gas shut off valves are open. 2. Check gas type, see Fig. 2, page 6. 3. Reset error code and open a water tap to cycle the heater in an effort to purge air on new installations. Cycling hot water tap on and off multiple times may be necessary. If heater still faults with EA error code, have a licensed gas technician properly purge air out of the gas line leading to the water heater. 4.
Electrical diagram 9 Electrical diagram 16 20 15 13 M M 12 M E PS 11 10 19 T=104°C T=220°F 18 9 T=110°C T=230°F 8 FS 7 6 Casc. 5 input Casc. 4 output Back flow 3 2 1 17 16 ... 1 20 ... 1 21 14 JP2 JP7 JP5 JP8 JP6 22 6720608542-04.1AL Fig.
Sensor resistance charts 10 Sensor resistance charts 110 222 2 17 2 12 207 202 19 7 19 2 18 7 18 2 177 172 16 7 16 2 157 152 14 7 14 2 13 7 13 2 12 7 12 2 117 112 10 7 10 2 97 92 87 82 77 72 67 62 57 52 47 42 37 32 10 5 10 0 95 90 85 80 75 70 65 60 55 50 Temp ºC Temp ºF Outlet temperature sensor characteristics 45 40 35 30 25 20 15 10 5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 Resistance (Kohm) Fig.
Sensor resistance charts 155 302 297 292 287 282 277 272 267 262 257 252 247 242 237 232 227 222 2 17 2 12 207 202 19 7 19 2 18 7 18 2 17 7 17 2 16 7 16 2 15 7 15 2 14 7 14 2 13 7 13 2 12 7 12 2 117 112 10 7 10 2 97 92 87 82 77 72 67 62 57 52 47 42 37 32 150 14 5 14 0 13 5 13 0 12 5 12 0 115 110 10 5 10 0 95 90 85 80 75 70 Temp ºC Temp ºF Back Flow characteristics 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
GWH 2700 ES Functional scheme 11 GWH 2700 ES Functional scheme Fig.
Interior components diagram and parts list 12 Interior components diagram and parts list 12.1 Interior components Fig.
Interior components diagram and parts list Fig.
Interior components diagram and parts list 12.2 Components diagram 12.2.1 Group 1 9 16 9 15 12 9 17 13 15 14 10 5 6 8 9 7 3 2 11 4 1 6720902973.AA JF Fig.
Interior components diagram and parts list 12.2.2 Group 2 3 2 1 5 4 8 9 6 7 6720902974.AA JF Fig.
Interior components diagram and parts list 12.2.3 Group 3 5 1 2 4 3 6 9 16 13 12 8 11 7 15 14 17 6720902975.AA JF Fig.
Interior components diagram and parts list 12.2.4 Group 4 14 11 10 13 12 11 6 7 9 1 8 2 5 3 4 6720608158-73.1AL Fig.
Interior components diagram and parts list 12.2.5 Group 5 Fig.
Interior components diagram and parts list 12.2.6 Group 6 4 8 5 6 7 9 10 11 3 2 1 14 15 16 12 13 6720902978.AA JF Fig. 72 Components Diagram Item Description Reference Item Description Reference 1 Control unit 8 707 207 257 9 Electrode cables 8 704 401 346 Flue gas limiter 8 700 400 032 2 Fuse T2.5A 1 904 521 342 10 3 Fuse T1.
Protecting the environment 13 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.
Limited Warranty 14 Limited Warranty General Aquastar water heaters are warranted by the Manufacturer (BOSCH) through Bosch Thermotechnology Corp.. Bosch thermotechnology corporation will furnish a replacement heat exchanger and will furnish a replacement of any other part which fails in normal use and service within the applicable periods specified below, in accordance with the terms of this warranty. The Bosch Thermotechnology Corp.
Limited Warranty 58 6 720 608 542
Limited Warranty 6 720 608 542 59
6720608542 Installer Checklist to be completed by installer upon installation Serial Number ___ ___ ___ ___ ___ ___ ___ ___ (8 digit serial number is located on rating plate on right side panel) Gas Pressure Reading* Static__________ Operating__________ Building Water Pressure __________ Range if on Well system __________ Installing Company _____________________________________________ Installer name _____________________________________________ Address ________________________________________
