CodeRegistry
Brands
  1. Home
  2. Bosch
  3. Heat Pumps
  4. Filter blocked
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

Filter blocked

Reduced efficiency — System filter blocked with dirt

Bosch · Heat Pumps

What does Filter blocked mean?

The system filter or filter ball (SC1) is obstructed by dirt, which can significantly reduce the efficiency of your Heat Pump and heating system.

Common Causes

  • Accumulation of dirt, debris, or sludge in the system filter.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Turn off the Heat Pump at the main power supply.

  2. 2

    Locate the system filter or filter ball SC1 in your heating system.

  3. 3

    Clean the filter according to the instructions in your Heat Pump's main manual.

  4. 4

    Restore power and monitor the system's performance.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

5203Alarm Outdoor sensor TL1 faulty5206Alarm Flow sensor T0 faulty5209Alarm Z1 heat transfer fluid out sensor TC1 faulty
Source: Bosch Heat Pumps
Open Manual (Page 4)Search more codes in this manual