Problem solving

Display

Cause

Solution

 

Over-temperature detected by

1. Check that the sensor is firmly attached to the vertical section of

 

outlet temperature sensor on hot

the hot water pipe (see Fig. 69, page 52).

 

water pipe.

2. Check red wire connections at outlet temperature sensor.

 

Temperature > 185°F

Clean terminals with an eraser. If badly corroded, replace sensor

 

 

and wire harness. Check sensor resistance (see Fig. 59, page

 

 

43.

3.Clean inlet filter screen per chapter 6.2, page 27 and clear any debris out of shower heads, faucet aerators and whole house filters.

4.In areas where water has a high mineral content, periodic descaling may be necessary. See chapter 6.3, page 27 for directions.

Cold water temperature

sensor

1. Check connector on wires coming from top of watervalve for a

fault.

 

secure connection. See Fig. 63, page 46.

 

 

2.

Sensor may trip if water temperature drops below freezing to

 

 

protect heater from freezing conditions Any damage due to

 

 

freezing conditions is not covered under warranty.

 

 

 

Backflow temperature sensor over

1.

Check combustion air and backflow vent piping for blockage.

309°F.

 

2.

Check if secondary fan connections are disconnected.

The appliance will close the burner

3.

Check venting specifications are met. Long vent lengths,

and lock.

 

venting with more than three elbows, blocked vent or combination

 

 

venting may cause this failure.

 

 

4.

Check sensor resistance (see Fig. 61, page 44).

 

 

 

Overheat sensor (ECO)

open

1. Disconnect power supply cord and check wire connections on

circuit (should reset when cooler

overheat sensor (top right of heat exchanger) and the two

temperatures are detected).

 

connectors on the control board. See Fig. 63, page 46.

 

 

2.

Check white wire connections at overheat sensor. Clean

 

 

terminals with an eraser. If badly corroded, replace sensor and

 

 

wire harness.

 

 

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.

Clean inlet filter screen and clear any debris out of shower

 

 

heads, faucet aerators and whole house filters.

 

 

5.

In areas where water has a high mineral content, periodic

 

 

descaling may necessary, see chapter 6.3.

 

 

6.

Unplug power supply cord to the water heater. Open a hot

 

 

water tap for several minutes to allow cold water to pass through

 

 

heat exchanger. Close hot water tap and disconnect lead wires to

 

 

overheat sensor. Using a multimeter, check continuity through

 

 

overheat sensor contacts. Replace sensor if open.

Table 20

* By installer or service technician only.

40

6 720 608 782

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Image 40
Bosch Appliances GWH 2400 ES LP, GWH 2400 ES NG manual Over-temperature detected by
Page 39 Page 41

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.
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