Bosch PROTANKLESS GWH 345/450 ESR - Manual (Page 32)

6 720 607 909
32
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