Bosch Appliances GWH-345/450-ESR-N Water Heater User Manual


 
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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 unit
1)
.
F7 "false flame" (error during self check of
electronic).
1. Check for moisture on the
Electronics
2. Check cables, sensor contacts
(corrosion)
3. Check flame inside Burner
chamber
4. Check electronic unit
1)
.
E0 Shut down because of low voltage. 1. Check power supply
2. Check electronic unit
1)
.
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 unit
1)
.
A7 Domestic hot water - Tank NTC defect
(no function)
1. Check domestic hot water
- NTC
2. Check cable (opened, short)
3. Check electronic unit
1)
.
AA Flow reduced 1. Check heat exchanger - flush or
descale if necessary
.
LED or LCD of the appliance doesn't
start up, no function.
No voltage supply, fuse blown,
transformer etc. defect
1. Check voltage supply
2. Check fuse
3. Check electronic unit
1)
.
Noise; boiling noise (over heating), no
correct function.
Low circulation, air inside installation,
bad heat transfer.
1. Check air in system, air vent
2. Check heating circulation
3. Check heat exchanger
4. Check gas type, injectors, gas
valve.
Table 16