Bosch Appliances 2400E LP Water Heater User Manual


 
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Troubleshooting
Display Cause Solution
E9 Temperature limiter opened circuit (overheat).
Trips at 220F (104C).
Check connections.*
Check heat exchanger condition.*
EA No ionization during safety time (safety time out).
Note: appliance makes 3 ignition attempts
before entering error mode “EA”.
Check gas pressure.*
Check that gas is not diluted with air, as a result
from recent gas pipeline rework.*.
Check if vent terminal is blocked (especially when
the appliance starts up for some seconds and then
looses ionization signal).*
Check ionization electrode.*
Check for a proper ground.*
EC The ionization signal momentarily disappeared
more then 5 times in less then 30 seconds.
FA Leakage error (gas valves do not close gas
circuit).
Check gas valve and control unit.*
F7 Ionization error (flame sensing at stand-by). Check control unit.*
E0 Internal software/hardware failure. Check control unit.*
A7 Hot water temperature sensor/receiver defect
(from control unit).
Check water temperature sensor/receiver and
connections.*
Check room area temperature where heater is
located, it must be above 36°F (2°C)
A9 Hot water temperature sensor/receiver mis-
assembled (from control unit).
Note: if display shows “A9” flashing, the
appliance can be operated normally, but
performance may be affected.
Close water tap and allow 30 seconds for purging
time.
Open water tap and wait for 2 minutes to see if A9
message is deleted from the display.
Check that the water temperature sensor/receiver is
properly assembled in the water pipe.*
Check that the water temperature sensor/receiver is
in proper condition.*
C1 FAN rotation too low at start-up (from control
unit).
Check supply voltage.*
Check fan and connections.*
Check control unit.*
Check if vent terminal is blocked or if vent terminal is
according with
chapter 2.9. *
Check CO
2
levels (see chapter 9).*
C6 FAN rotation too low at operation (from control
unit).
Check supply voltage.*
Check fan and connections.*
Check control unit.*
Check if vent terminal is according with
chapter 2.9.*
C7 No rotational speed sensor signal from FAN Check fan and connections.*
Check control unit.*
Check CO
2
levels (see chapter 9).*
CA Water flow signal over specified maximum value Check water valve and flow sensor.*
E2 Inlet temperature sensor fault Check water temperature sensor/receiver and
connections.*
Check room area temperature where heater is
located, it must be above 36°F (2°C)
A2 Overheat protection fault Check connections to the overheat protection.*
Check sensor continuity.*
Check heat exchanger sealings and walls.*
Table 7
* By installer or service technician only.