Verified boiler fault code
Sime ALL 91 Fault Code (Brava Slim HE ErP)
Gas valve out of range.
Safety disclaimer
Fault code summary
- Manufacturer
- Sime
- Fault code
- ALL 91
- Fault type
- Gas valve, Gas supply
- Severity
- high
- Reset
- The official solution is gas-valve recalibration by a qualified engineer; no 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
Gas valve out of range.
What does this fault code mean?
Gas valve out of range.
Common causes
- Gas valve operating value out of range
Symptoms
- ALL 91 alarm displayed
What can the homeowner safely check?
- Do not adjust the gas valve; record the alarm and arrange qualified service.
Boiler reset information
The official solution is gas-valve recalibration by a qualified engineer; no 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 and recalibrate the gas valve using the Sime procedure.
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 03 — Brava Slim HE ErP
High water pressure in the heating circuit.
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
Manufacturer documentation
Brava Slim HE ErP installation, use and maintenance manual (official Sime document 6322841C)Official manual fault table: | ALL | 91 | Gas valve out of range | - Recalibrate the gas valve |
Last verified
2026-09-12
Frequently asked questions
What does Sime ALL 91 mean?
Gas valve out of range.
Can I reset a Sime ALL 91 fault?
The official solution is gas-valve recalibration by a qualified engineer; no homeowner reset is confirmed.