Verified boiler fault code
Sime ALL 03 Fault Code (Brava Slim HE ErP)
High water pressure in the heating circuit.
Safety disclaimer
Fault code summary
- Manufacturer
- Sime
- Fault code
- ALL 03
- Fault type
- High pressure, Central heating
- Severity
- high
- Reset
- The official table gives a pressure-adjustment instruction for qualified service; no unrestricted homeowner reset is confirmed.
- Applicable models
- Brava Slim HE ErP 25, Brava Slim HE ErP 30, Brava Slim HE ErP 35, Brava Slim HE ErP 40
Quick answer
High water pressure in the heating circuit.
What does this fault code mean?
High water pressure in the heating circuit.
Common causes
- High circuit water pressure
Symptoms
- ALL 03 alarm displayed
What can the homeowner safely check?
- Check the pressure reading on the boiler and stop if it is unusually high; do not dismantle or drain the appliance.
Boiler reset information
The official table gives a pressure-adjustment instruction for qualified service; no unrestricted homeowner reset is confirmed.
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 the heating-circuit pressure, expansion vessel and pressure-relief arrangements.
Applicable boiler models
Related fault codes
- ALL 01 — Brava Slim HE ErP
Flue-gas thermostat fault.
Read fault code - ALL 02 — Brava Slim HE ErP
Low water pressure in the appliance.
Read fault code - ALL 44 — Brava Slim HE ErP
No-flame gas-valve opening-time sum anomaly.
Read fault code - ALL 56 — Brava Slim HE ErP
Lock for delivery/return temperature difference above the maximum limit.
Read fault code - ALL 57 — Brava Slim HE ErP
Lock for the flow-temperature check (open-vent model).
Read fault code - ALL 62 — Brava Slim HE ErP
Self-calibration procedure required.
Read fault code - ALL 72 — Brava Slim HE ErP
Incorrect positioning of the delivery sensor.
Read fault code - ALL 74 — Brava Slim HE ErP
Second delivery sensor fault.
Read fault code
Manufacturer documentation
Brava Slim HE ErP installation, use and maintenance manual (official Sime document 6322841C)Official manual alarm table: | ALL | 03 | Alta pressão água circuito |
Last verified
2026-09-12
Frequently asked questions
What does Sime ALL 03 mean?
High water pressure in the heating circuit.
Can I reset a Sime ALL 03 fault?
The official table gives a pressure-adjustment instruction for qualified service; no unrestricted homeowner reset is confirmed.