Installation / Operation Instruction Manual
51
Problem solving
RTG-K-199/160N/X2 – 6 720 813 642 (2022/06)
9Problem solving
9.1 Error code diagnostics
To remove error codes from the display,
▶ Press the ON/OFF button more than 3 sec. (long press).
Installation, maintenance and repair must only be carried out
by qualified contractors. The following table describes the
solutions for possible problems.
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 (70 °C). Appliance regulates power to
protect against overheat.
▶ External air temperature is above 140 °F (60 °C).
▶ Check for flue leakages inside the appliance.
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 4.12).
▶ Replace the sensor and/or wire connections, if the
problem persists.
1)
A3 Flue gases temperature sensor [15] disconnected
or damaged.
▶ 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)
A9
3)
Incorrect output power (too low). ▶ Check gas inlet pressure
1)
( section 4.17).
▶ Check water temperature sensors [17][19][20]
and water flow sensor [14] wire connections.
▶ Check connections or replace sensor
(section 11), replace any if it is not according to
specification.
1)
2)