Download  Print this page

Problem Solving; Error Code Diagnostics - Bosch Greentherm T9900 SE 160 Installation And Operating Instructions Manual

Indoor residential tankless water heaters, 160 000/199 000 btu- natural gas 160 000/199 000 btu - liquefied petroleum lp gas
Hide thumbs

Advertisement

9

Problem solving

9.1

Error code diagnostics

To remove error codes from the display,
▶ Touch the On/Off button more than 3 sec. (long press).
Display
Description
A0
Water temperature sensors [17] [19] [20]
disconnected or damaged.
A1
Air temperature inside the cabinet [18] is above
158 °F (70 °C). Appliance regulates power to
protect against overheat.
A2
External water temperature sensor/aquastat [21]
disconnected, damaged or not properly installed.
A3
Flue gases temperature sensor [15] disconnected
or damaged.
A4
Air temperature sensor [18] disconnected or
damaged.
A5
Condensing unit flue temperature sensor [16]
disconnected or damaged.
A6
Inlet cold water temperature sensor [20]
disconnected or damaged.
A7
Heat exchanger hot water temperature sensor [16]
disconnected or damaged.
A8
Outlet hot water temperature sensor [17]
disconnected or damaged.
A9
Incorrect output power (too low).
Greentherm T9900 SE/i – 6 720 813 635 (2019/03)
Installation, maintenance and repair must only be carried out
by qualified contractors. The following table describes the
solutions for possible problems.
Solution
▶ Check sensor wire connections.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ External air temperature is above 140 °F (60 °C).
▶ Check for flue leakages inside the appliance or in
concentric vent.
▶ Check temperature sensor and associated
1) 2)
connections.
▶ Check sensor position in the tank pocket.
▶ Verify if correct recirculation settings are in use
(section 6.5.2).
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check sensor wire connections.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check sensor wire connections.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check sensor wire connections.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check sensor wire connections.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check sensor wire connections.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check connections or replace sensor.
▶ Replace the sensor and/or wire connections, if the
problem persists.
▶ Check gas inlet pressure
▶ Check water temperature sensors [17][19][20]
and water flow sensor [14] wire connections.
▶ Check sensors resistance and water flow sensor(
section 11) and replace any if it is not according to
1) 2)
specification.
Problem solving
1) 2)
1)
1)
1)
1) 2)
1)
1) 2)
1)
1) 2)
1)
1) 2)
1)
1) 2)
1)
1) 2)
1)
1)
( section 4.13).
67

Advertisement

loading

  Related Manuals for Bosch Greentherm T9900 SE 160

This manual is also suitable for:

Greentherm t9900 se 199Greentherm t9900 se/i 199