Bosch Appliances GWH 2400 ES NG manual Troubleshooting, Water is too hot, Water is not hot enough

Page 35

Troubleshooting

7Troubleshooting

Warning: If you are unable to perform the tasks listed below, or need additional assistance please contact your original installer or licensed gas technician.

7.1Introduction

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. For best results, perform each step before proceeding to the next. The suggested solutions may require that the cover be taken off. (See Page 6. Fig. 3).

7.2Burner do not ignite when hot water is turned ON

1.If the display is blank, verify power to outlet. (120VAC/60Hz properly grounded circuit required). Verify that the heater ON/OFF button is turned ON.

2.Verify the fuses in the control board are good. See Section 4.2, page 23 of the installation manual for fuse locations.

3.Make sure cold water inlet connection is plumbed to the right side of heater when facing unit. See Fig. 28, page 20.

4.A minimum of 0.65 gallons per minute (GPM) (2.5 l/

m)is required to activate the heater. A quart container should fill in 25 seconds or less to activate heater. In areas of warm inlet water temperatures, the heater may increase activation rate to as high as 1.6 gallons per minute (GPM) to prevent overshooting of set temperature.

5.Clean inlet filter screen per chapter 6.2, page 27.

6.Inspect the water path for obstructions. Make sure all showerheads, faucet aerators and whole house filters are clear of debris.

7.The heater activates when the water flow through the unit is at or above the required minimum of 0.65 GPM (2.5 l/m). A crossover in the plumbing creates back pressure on the water flowing through the heater. Therefore, a higher flow rate than normal is needed to force the heater to activate. To check for a plumbing crossover, shut off the cold water supply to the water heater. Then open all of the hot water taps served by the heater. Wait 10 minutes and check for water flow at taps. There should be no water flowing. Any continuous flow of water, small or large, indicates a crossover is present 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.With the ON/OFF switch turned to OFF (O) position and the power supply cord unplugged, remove the unit's front cover (See Page 6. Fig 3). Check wire connections between the water valve, control unit and electrode set. See chapter 12.1, page 46 for location of these parts.

7.3Water is too hot

1.Selected temperature on the unit is set too high. To lower output temperature, see chapter 5.4, page 25.

2.Clean inlet filter screen per chapter 6.1, page 27.

3.Inspect the water path for obstructions. Make sure all showerheads, faucet aerators and whole house filters are clear of debris.

4.Confirm the heater's gas type coincides with the type of gas being supplied. See Fig. 2, page 5 for location of rating plate.

5.Avoid restrictive outlets. Clean all showerheads and faucet aerators. It may be necessary to upgrade to higher flow rate shower heads if allowable by local code.

6.In areas where the water has a high mineral content, periodic descaling may necessary. See chapter 6.3, page 28 for directions.

7.Ensure the outlet temperature sensor is making contact and firmly mounted on the hot water pipe.

7.4Water is not hot enough

1.Selected temperature on the unit is too low. To raise output temperature, see chapter 5.4, page 25.

2.Clean inlet filter screen. See chapter 6.1, page 27.

3.Inspect the water path for obstructions. Make sure all showerheads, faucet aerators and whole house filters are clear of debris.

4.Confirm the heater's gas type coincides with the type of gas being supplied. See Fig. 2, page 5 for location of rating plate.

5.Check inlet gas particle screen for blockage at gas inlet connection on bottom of unit.

6.Verify gas pressure is in accordance with specifications in chapter 3.12, page 22. A gas pressure reading is needed to proceed further. Contact your original installer or a local certified gas technician to obtain this reading.

7.Cold water is mixing into the hot water lines (plumbing crossover). A plumbing crossover can unintentionally mix cold water with the hot water leaving the heater. The end result is a cooler water temperature than desired. To check for a plumbing crossover, shut off the cold water supply to the water heater. Then open all of the hot water taps served by

6 720 608 782

35

Page 34 Page 36
Image 35
Page 34 Page 36
Contents What to do if you smell gas Intended for variable flow applicationsIndex FCC For your safetyAppliance details FeaturesGWH 2400 ES Specifications Technical data Unpacking the GWH 2400 ES heater Appliance details To remove front cover To remove combustion cover service onlyGeneral rules to follow for safe operation Dimensions Dimensions and Minimum installation clearancesVenting Installation instructionsTools required for installation IntroductionFittings or Piping Equivalent Feet Vent Safety SystemDescription Minimum distance Installation instructions Venting configuration examples Venting Flex ProTech Heat Fab Installation instructions Condensate drain requirementsRoom sealed installation Twin Pipe System Exhaust Determining installation adjustmentInstallation instructions Vent connections Twin pipe Combustion air requirementsMounting installation Proper location for installing your heaterHeater placement and clearances Gas piping & connections GAS Connections For Natural GAS Water quality Water connectionsRecirculation application Recirculation applicationMeasuring gas pressure Position of the fuses in control unit Electrical power supplyElectrical connections LCD Display functions Operation instructionsTemperature selection For your safety read before operating your water heaterPower Program button Use of optional remote control accessory part no. TSTAT2Reset button OperationWinterizing for seasonal use Maintenance and serviceAnnual maintenance table Every year Annual maintenanceMineral scale build-up Adjusting CO2 carbon dioxideDescaling using a pump Once Gas Pressure is adequate Measuring CO2 combustion cover must be installedAdjusting CO2 Returning to Service% 2.8 % 60 ppm Final ReadingsComment Program Description Factory DefaultProgram values Diagnostic menu Control board diagnosticsExample Fan speed adjustmentTotal vent length calculation IntakeMode Pipe Length1 Fan speed Maintenance and service To select fan speedWater is not hot enough TroubleshootingTroubleshooting Water is too hotNoisy burner/heater during operation Hot water temperature fluctuates at tapLow water flow/pressure Troubleshooting Error code diagnostics Problem solvingVenting may cause this failure Problem solving Display Cause SolutionOver-temperature detected by No flame ionization detected with Electrical diagram Electrical diagramSensor resistance charts Back Flow characteristics Functional scheme GWH 2400 ES Functional schemeInterior components Interior components diagram and parts listInterior components diagram and parts list Appliance overview Item Description Components diagramGroup Description ReferenceInterior components diagram and parts list Group Interior components diagram and parts list Group Interior components diagram and parts list Group Interior components diagram and parts list Group 708 300 Components Protecting the environmentProtecting the environment PackingLimited Warranty Bosch Thermotechnology Corporation

GWH 2400 ES NG, GWH 2400 ES LP specifications

Bosch Appliances has established a reputation for delivering high-quality and innovative home solutions, and the Bosch GWH 2400 ES LP and GWH 2400 ES NG are no exceptions. These high-efficiency water heaters are designed to provide on-demand hot water, ensuring comfort and convenience for your home.

One of the standout features of the Bosch GWH 2400 ES LP (Liquid Propane) and GWH 2400 ES NG (Natural Gas) models is their compact, space-saving design. These tankless water heaters are engineered to fit in smaller spaces, making them an ideal choice for homes with limited installation areas. Despite their compact size, both models provides a powerful performance that meets the hot water needs for multiple fixtures simultaneously, such as showers, faucets, and washing machines.

These water heaters are equipped with advanced technology that enables precise temperature control. The Bosch GWH 2400 ES series utilizes a microprocessor-based control system that allows for consistent water heating, ensuring the water temperature remains stable even during high demand. The modulating gas valve further optimizes energy consumption, adjusting the flame intensity to meet the exact heating needs, thus enhancing efficiency.

In terms of safety, both the GWH 2400 ES LP and NG come with multiple safety features. These include a flame failure safeguard, overheating protection, and a built-in freeze protection system. Such features ensure both peace of mind and the longevity of the unit.

Installation is straightforward with these models, as they can be vented using standard venting materials, saving time and costs. Additionally, the units boast a low NOx emissions rating, making them environmentally friendly choices that help homeowners reduce their carbon footprint.

Maintenance is minimal, thanks to the corrosion-resistant heat exchanger which ensures durability and long service life under normal operating conditions. This factor, combined with Bosch’s renowned commitment to quality, makes these models a reliable investment for any household.

Whether you opt for the GWH 2400 ES LP or the GWH 2400 ES NG, you will experience the benefits of a powerful, efficient, and safe water heating solution tailored to your specific household needs. Bosch has truly combined technology, sustainability, and user comfort in these innovative models, solidifying their place as leaders in the home appliance market.
Top Page Image Contents