Bosch Greentherm 9800 SECO 199, Installation And Operating Instructions Manual

Page: 38 / 52

6 720 817 281 (2017/05) Greentherm 9800 SEO 160/199 | SECO 199
38 | Problem solving
11 Problem solving
11.1 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,
▶ Press the ON/OFF button more than 3
sec. (long press).
Display Description Solution
A0 Water temperature sensors [17] [19] [20]
disconnected or damaged. ▶ Check sensor wire connections.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A1 Air temperature inside the cabinet [18] is above
158 °F. Appliance regulates power to protect
against overheat. ▶ External air temperature is above 140 °F.
▶ Check for flue leakages inside the appliance or in
concentric vent.
1)
A2 External water temperature sensor/aquastat [21]
disconnected, damaged or not properly installed. ▶ Check temperature sensor and associated
connections.
1) 2)
▶ Check sensor position in the tank pocket.
▶ Verify if correct recirculation settings are in use
(

section 6.4.1).
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A3 Exhaust temperature sensor fault [15]. ▶ Check sensor wire connections.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A4 Air temperature sensor [18] disconnected or
damaged. ▶ Check sensor wire connections.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A5 Condensing unit flue temperature sensor [16]
disconnected or damaged. ▶ Check sensor wire connections.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A6 Inlet cold water temperature sensor [20]
disconnected or damaged. ▶ Check sensor wire connections.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A7 Heat exchanger hot water temperature sensor
[16] disconnected or damaged. ▶ Check sensor wire connections.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A8 Outlet hot water temperature sensor [17]
disconnected or damaged. ▶ Check connections or replace sensor.
1) 2)
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
Table 20