What F91 Means
F91 on an older Bosch Evolution range means the control has tried to unlock the oven door the maximum number of times allowed and given up. Where F90 records a single attempt taking too long, F91 records repeated attempts failing, which usually points at a mechanism that is binding rather than one that simply moves slowly.
Common Causes of F91
- Lock mechanism binding mechanically
- Lock motor cam not reaching the switch plunger
- Lock motor switch contacts failed
🔧 One Safe Check You Can Try
Let the oven cool completely first, since a self-clean lockout leaves the cavity far hotter than ordinary cooking; once it is cold, cut power at the breaker for several minutes to let the control start its unlock sequence fresh. Do not pry at the door.
⚠ Why You Shouldn't Go Further Than That
- Repeated failed attempts mean the mechanism has already been driven against resistance several times, so the cam and strike may already be distorted.
- The manual's test advances the motor by hand until the cam depresses the switch plunger, which requires the assembly to be accessible and de-energised.
- On gas and dual fuel models the appliance gas valve must be shut off before the fascia area is opened.
- Levering a door that the control is still trying to unlock risks damage to both the door and the frame.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.