Viessmann F2: flow temperature sensor fault on a Vitodens
Vitodens boilers give more diagnostic detail on their control panel than most rivals, and F2 is best approached by reading that history menu rather than resetting first. The stored fault log usually shows exactly when the reading went out of range.

How we read a Viessmann F2 sensor fault on site
A sensor reading that jumps instantly to an implausible extreme is usually a wiring fault — a corroded plug or a chafed connector — rather than the sensor element itself failing gradually. A reading that drifts slowly over weeks points more towards genuine sensor degradation or a build-up of deposit changing its response time. The control menu's stored history is checked before any component is opened up.
What matters most with a Viessmann F2 sensor fault
- The control panel's fault history shows exactly when it occurred
- A sudden jump to an extreme reading suggests a wiring fault
- A slow drift over weeks suggests genuine sensor degradation
- Corroded plugs are checked before the sensor is condemned
- Deposit build-up on the sensor changes its response speed
Where we deal with this
Relevant registrations
- Gas Safe registered for domestic gas boiler work
- OFTEC registered for oil boiler work
- Worcester Bosch Accredited Installer
Book a visit for a Viessmann F2 sensor fault
The honest position: Read the history before resetting — Viessmann's own diagnostic menu often narrows F2 before a tool is even picked up.
Call Jamie Crawford Heating on 07516 118198 during the published weekday opening hours.
Related help pages
- Electrical faultRCD tripping every time the boiler tries to start
- Circulation faultBoiler hot but radiators cold: pump, valve and airlock diagnosis
- ElectronicsBoiler PCB failure: when the circuit board really is the problem
- Fault differentiationIdeal L2: why the same code means different repairs
- Contractor paperworkWhat paperwork landlords should expect from a heating contractor
- Brand comparisonWorcester Bosch vs Ideal boilers
Services that cover this
Questions we get asked
- Can I read the fault history myself?
- The Vitodens menu is accessible to homeowners, but interpreting the codes correctly is best left to an engineer familiar with Viessmann's system.
- Are Viessmann parts harder to source?
- Availability is generally good through official channels, though lead times can vary by component.
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