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Bosch · Heat pump

F2 System lockout (5 low-pressure trips in 100 minutes)

High severity Bosch IDS LightBosch IDS Premium Connected

What the control is telling you

The unit locked out after repeated low-pressure protection (P21/P2). A hard restart is required.

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

  • Closed service valves
  • Undercharge
  • Blockage or poor heat exchange
  • Failed transducer

Test and repair steps

  1. Fix the cause of the low-pressure trips (see P21).
  2. Hard restart the system after repair.

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

  • E51 Input voltage out of range
  • E52 DC bus voltage out of range
  • E81 EEV coil fault
  • F1 High pressure switch protection
  • F4 Pressure transducer fault
  • F41 High pressure sensor fault
  • F42 Low pressure sensor fault
  • H01 Drive chip communication 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.