Verified boiler fault code
Biasi E04 Fault Code (BASICA COND)
Pump circulation failure or insufficient system pressure.
Safety disclaimer
Fault code summary
- Manufacturer
- Biasi
- Fault code
- E04
- Fault type
- Pump, Circulation, Low pressure
- Severity
- high
- Reset
- Use the manufacturer Reset key only where the user manual permits it; do not repeatedly reset if circulation or pressure remains abnormal.
- Applicable models
- BASICA COND 24C, BASICA COND 28C, BASICA COND 32C
Quick answer
Pump circulation failure or insufficient system pressure.
What does this fault code mean?
Pump circulation failure or insufficient system pressure.
Common causes
- Pump circulation failure
- Insufficient system pressure
Symptoms
- E04 shown on the LCD
What can the homeowner safely check?
- Check the heating pressure display/gauge and normal controls; do not access the pump or boiler casing.
Boiler reset information
Use the manufacturer Reset key only where the user manual permits it; do not repeatedly reset if circulation or pressure remains abnormal.
When should I call an engineer?
Contact a suitably qualified heating engineer when the fault persists, the boiler locks out, or the manufacturer instructions do not resolve it. For gas appliance work in the UK, use a Gas Safe registered engineer.
Engineer diagnosis
- A qualified engineer should assess system pressure, pump operation, circulation and wiring.
Applicable boiler models
Related fault codes
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Heating NTC probe failure.
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External NTC probe failure.
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Read fault code
Manufacturer documentation
Biasi BASICA COND user manual and installation instructionsSIGNAL DISPLAYED BY THE LCD: | E04+ | Pump circulation failure or insufficient system pressure |
Last verified
2026-09-12
Frequently asked questions
What does Biasi E04 mean?
Pump circulation failure or insufficient system pressure.
Can I reset a Biasi E04 fault?
Use the manufacturer Reset key only where the user manual permits it; do not repeatedly reset if circulation or pressure remains abnormal.