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Bosch · Heat pump

b7 R-454B refrigerant leak protection

Critical severity Bosch IDS LightBosch IDS Premium Connected

What the control is telling you

The indoor refrigerant sensor has detected a leak.

Applies to: Bosch IDS Light BOVA15-24/36/60 and IDS Premium Connected BOVA36-20/60-20 R-454B heat pump outdoor units

Likely causes

  • Refrigerant leak at line set or coil
  • Other flammable gases near the sensor
  • Failed sensor

Test and repair steps

  1. Warning: Ventilate the space and remove ignition sources before servicing.
  2. Leak-check the line set and coil; recover refrigerant and repair or replace the line set.
  3. Rule out other flammable gases, then replace the refrigerant sensor if no leak is found and restart.

Models that show this code

5 models in Bosch IDS Light, Bosch IDS Premium Connected

BOVA15-24BOVA15-36BOVA15-60BOVA36-20BOVA60-20

Other codes on the same units

  • b2 Indoor T2 sensor fault
  • b3 Indoor refrigerant sensor hardware fault
  • b4 Indoor refrigerant sensor communication fault
  • b5 Indoor to outdoor communication fault
  • b8 Refrigerant sensor past service life
  • C3 T3 coil sensor not reading correctly in cooling
  • E7 T5 discharge sensor not reading correctly
  • E41 T3 temperature sensor fault

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Source: Bosch IDS Light installation BTC 762003308 D (02.2025), Fault Code Table 23 and 17.12 Error Code Troubleshooting, p.42-59; Bosch IDS Premium Connected installation BTC 762003301 D (02.2025), Fault Code Table 22 and 18.12 Error Code Troubleshooting. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.