Troubleshooting

6	Troubleshooting

Fault Indication		Possible Cause	Check

E9		Shut down by the temperature limiter	• 1. Check position of heating NTC
		(over temperature).	• 2. Check temperature limiter, cables
			• 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).
F7		"false flame" (error during self check of	• 1. Check for moisture on the
		electronic).		Electronics
			• 2. Check cables, sensor contacts
				(corrosion)
			• 3. Check flame inside Burner
				chamber
			• 4. Check electronic unit1).
E0		Shut down because of low voltage.	• 1. Check power supply
			• 2. Check electronic unit1).
F0		Internal error in the electronic unit.	• 1. Check electronic unit connections
				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 electronic unit1).
A7		Domestic hot water - Tank NTC defect	• 1. Check domestic hot water - NTC
		(no function)	• 2. Check cable (opened, short)
			• 3. Check electronic unit1).
AA		Flow reduced	• 1. Check heat exchanger - flush or
				descale if necessary.

LED or LCD of the appliance doesn't		No voltage supply, fuse blown,	• 1. Check voltage supply
start up, no function.		transformer etc. defect	•	2. Check fuse
			• 3. Check electronic unit1).
Noise; boiling noise (over heating), no		Low circulation, air inside installation,	• 1. Check air in system, air vent
correct function.		bad heat transfer.	• 2. Check heating circulation
			• 3. Check heat exchanger
			• 4. Check gas type, injectors, gas
				valve.

Table 16

32	6 720 607 909

GWH-345/450-ESR-L, GWH-345/450-ESR-N specifications

Bosch Appliances has long been recognized for its innovative and high-quality home appliances, and the GWH-345/450-ESR-N and GWH-345/450-ESR-L water heaters are no exception. These models offer exceptional efficiency and reliability, making them ideal choices for modern households seeking dependable water heating solutions.

One of the standout features of the GWH-345/450-ESR series is their impressive energy efficiency. Engineered with cutting-edge technology, these units operate with high thermal efficiency ratings. This not only translates to reduced energy bills for consumers but also supports environmentally friendly practices by minimizing energy consumption. The tankless design eliminates the need for a storage tank, providing hot water on demand while ensuring that no energy is wasted in heating and re-heating stored water.

Both models come equipped with advanced safety features. The integrated combustion management system ensures precise control of the combustion process, which not only enhances heating efficiency but also reduces the risk of overheating. Additionally, the built-in safety mechanisms, such as flame failure protection and overheat protection, provide consumers with peace of mind knowing their home is protected.

These Bosch water heaters also feature a user-friendly digital display that allows for easy temperature adjustment and monitoring. The intuitive interface enables users to set their desired water temperature with precision, ensuring comfort and convenience. Furthermore, these models are designed for quiet operation, making them suitable for installation in various locations within the home without causing disruptive noise.

The construction of the GWH-345/450-ESR-N and GWH-345/450-ESR-L models is robust, featuring high-quality materials that ensure durability and longevity. The compact and sleek design allows for flexible installation options, even in smaller spaces. With a variety of venting options available, including direct vent and power vent configurations, these heaters can fit seamlessly into different home layouts.

In summary, Bosch Appliances GWH-345/450-ESR-N and GWH-345/450-ESR-L models represent the pinnacle of modern water heating technology. With their energy-efficient performance, advanced safety features, user-friendly controls, and durable construction, these water heaters are designed to meet the demands of today’s homes while delivering reliable hot water whenever needed. These innovative appliances reinforce Bosch's reputation as a leader in home heating solutions, ensuring that customers can enjoy hot water with confidence and peace of mind.