mypros+
Error code reference

Bosch Refrigerator Error Code rt

Room temperature sensor (RT-sensor) disconnection or short circuit (full down).

Bosch codesBosch refrigerator codes

Room temperature sensor (RT-sensor) disconnection or short circuit (full down).

First step from the service manual

Measure the voltage of 'A' part on the Main PCB. If 0.5V-4.5V it is normal. If 0V (short) or 5V (disconnected), change the RT-sensor on the Main PCB.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

MyPros+ Max

Get the full diagnostic procedure for rt.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What rt means on a Bosch refrigerator

The rt error code on a Bosch refrigerator indicates a fault with the Room Temperature sensor, also called the RT-sensor. This sensor monitors the ambient temperature surrounding the refrigerator and feeds that data to the Main PCB. The Main PCB uses this information to make control decisions, particularly around compressor cycling and energy efficiency adjustments based on the room environment. When the code appears, the unit has detected either a short circuit (sensor signal pulled fully to ground) or a complete disconnection (open circuit) in the RT-sensor circuit.

The diagnostic process centers on measuring the voltage at the 'A' test point on the Main PCB. Under normal operating conditions, the RT-sensor produces a voltage signal between 0.5V and 4.5V, which varies with ambient temperature. A reading of 0V indicates a short circuit condition, where the sensor or its wiring has created a direct path to ground, collapsing the signal. A reading of exactly 5V indicates the circuit is open, meaning the sensor has become disconnected, the wiring harness has broken continuity, or the sensor itself has failed in an open state.

In both fault conditions, the corrective action is replacement of the RT-sensor on the Main PCB. Because the sensor is associated directly with the Main PCB, it may be integrated into the board assembly or mounted nearby with a dedicated connector. Technicians should inspect the connector and wiring harness for corrosion, damage, or loose seating before condemning the sensor itself, as wiring issues can produce the same voltage readings as a failed sensor.

Source: manufacturer service documentation.

Common causes of rt

  1. 01

    Failed RT-sensor

    Part replacement

    The RT-sensor itself has failed internally, either shorting to ground (causing a 0V reading) or breaking open (causing a 5V reading). This is the most common root cause and requires replacing the sensor.

  2. 02

    Disconnected or loose sensor connector

    Wiring / connection

    The wiring connector linking the RT-sensor to the Main PCB has come loose or fully separated, resulting in a 5V open-circuit reading at the 'A' test point. Inspecting and reseating the connector may resolve the fault.

  3. 03

    Damaged wiring harness

    Part replacement

    A wire in the RT-sensor harness has broken, frayed, or been pinched, disrupting the signal path to the Main PCB. This can produce either a 0V or 5V reading depending on whether the damage causes a short or an open circuit.

  4. 04

    Corrosion at the sensor connector

    Wiring / connection

    Moisture intrusion at the connector pins can cause corrosion that increases resistance, disrupts the signal, or creates a partial short. Corroded connectors may produce abnormal voltage readings even if the sensor itself is intact.

  5. 05

    Main PCB fault at the sensor input

    Part replacement

    In rare cases, the fault originates at the 'A' input circuit on the Main PCB rather than in the sensor or wiring. If the sensor and harness test correctly but the voltage reading is still 0V or 5V, the Main PCB may require further evaluation or replacement.

See the test procedure for each cause

Frequently asked questions about rt

What does rt mean on a Bosch refrigerator?
The rt code indicates a problem with the Room Temperature sensor (RT-sensor), which monitors the ambient temperature around the refrigerator. The Main PCB has detected that the sensor signal is either at 0V (short circuit) or at 5V (disconnected/open circuit), both of which fall outside the normal 0.5V to 4.5V operating range. The fault can originate in the sensor itself, the wiring harness, or the connector between the two.
Can I fix the rt error code myself?
Some causes of the rt code, such as a loose or disconnected sensor connector, can be addressed without specialized tools by reseating the connector at the Main PCB. However, properly diagnosing the fault requires measuring voltage at the 'A' test point on the Main PCB with a multimeter. If the sensor itself has failed, replacing it requires comfort working around refrigerator electronics, and mishandling the PCB can cause additional damage.
Is a Bosch refrigerator with the rt error code safe to use?
The rt error relates to the ambient room temperature sensor rather than the internal food compartment sensors, so the refrigerator may continue cooling to some degree. However, the unit cannot fully optimize its operation without this input, and performance may be affected. It is best to have the fault diagnosed and repaired promptly rather than continuing to run the appliance with an active sensor fault.
How much does it cost to repair the rt error on a Bosch refrigerator?
Repair costs depend on whether the issue is a simple connector problem or requires a new RT-sensor. Parts costs for a replacement sensor typically fall in the range of $20 to $80, while professional labor for diagnosis and repair can add $100 to $250 or more depending on your location and the service provider. If the Main PCB itself is found to be at fault, costs will be significantly higher.
Will resetting my Bosch refrigerator clear the rt error code?
A power reset may temporarily clear the rt code from the display, but the error will return if the underlying sensor fault has not been corrected. Because the code is triggered by a specific electrical condition (0V or 5V at the sensor input), the refrigerator will detect the fault again as soon as it runs its diagnostics. A proper repair, addressing the sensor, wiring, or connector, is required to permanently resolve the error.

Related Bosch refrigerator codes

All Bosch refrigerator codes
View all 209 Bosch refrigerator codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass