Bosch Greentherm 9800 SE 160/199, Manual

Page: 54 / 64

6 720 816 815 (2016/10) Greentherm 9800 SE 160/199 | SEC 199
54 | Problem solving
9 Problem solving
9.1 Error code diagnostics
Installation, maintenance and repair must only be carried out
by qualified contractors. The following table describes the
solutions for possible problems.
To remove error codes from the display,
▶ Touch the On/Off button more than 3
sec. (long press).
Display Description Solution
A0 Either cold or hot water temperature sensor fault. ▶ Check temperature sensors and associated
connections.
1) 2)
▶ Call a qualified contractor.
A1 Temperature inside the cabinet is above 158 °F. The appliance automatically regulates the
performance of the appliance to avoid overheating.
▶ External air temperature is above 140 °F.
▶ Check for flue leakages inside the appliance or in
concentric vent.
1)
AA Flue gas temperatures above 356 °F after the
primary heat exchange and/or 176 °F at the
exhaust sensor. The appliance is protected against overheating.
▶ Descale appliance.
1)
▶ Check if inlet water temperature is above
maximum limit.
A2 Tank temperature sensor is not properly installed.
Temperature sensor fault. ▶ Check temperature sensor and associated
connections.
1) 2)
▶ Check sensor position in the tank pocket.
▶ Check recirculation sub-menu in HMI.
A3 Flue gas temperature sensor fault. ▶ Check connections or replace sensor.
1) 2)
A4 Cabinet air temperature sensor fault. ▶ Check connections or replace sensor.
1) 2)
A5 Primary heat exchanger gas temperature sensor
fault. ▶ Check connections or replace sensor.
1) 2)
A6 Inlet water temperature sensor fault. ▶ Check connections or replace sensor.
1) 2)
A7 Heat exchanger temperature sensor fault. ▶ Check connections or replace sensor.
1) 2)
A8 Outlet water temperature sensor fault. ▶ Check connections or replace sensor.
1) 2)
A9 Incorrect output power.
Hot water temperature sensor is not installed
properly.
Incoming gas pressure too low (below 3.5" W.C.
for NG or 8" W.C. for LP)
▶ Check incoming gas pressure.
1)
▶ Check hot water temperature sensor.
C5 Fault in the bypass valve. ▶ Check bypass valve connections.
1)
C7 Fan not working. ▶ Check fan connections.
▶ Close and open a hot water tap.
C8 Main water valve disconnected. ▶ Check water valve connections.
1) 2)
C9 Barometric pressure sensors fault. ▶ Replace Electric Control Unit (ECU).
1) 2)
Table 26