How to fix Viessmann Vitodens 200-W fault code F22

What does the Viessmann Vitodens 200-W F22 fault code mean?

The F22 fault code indicates a dry fire condition or low water pressure in the Viessmann Vitodens 200-W boiler. This typically means that the boiler is unable to operate safely due to insufficient water in the system.

Common Causes

  • Low Water Pressure: This can occur due to leaks in the heating system or insufficient water being added to the system.
  • Dry Fire Condition: This may happen if the boiler has been running without sufficient water, potentially due to a malfunctioning pressure relief valve or an airlock.

Can I fix it myself? (DIY)

You can attempt to fix low water pressure by checking the pressure gauge and refilling the system if it is below 1 bar. However, if the issue persists or if you suspect a gas or electrical fault, it is crucial to call a Gas Safe Engineer.

Estimated Repair Cost (2026 UK Prices)

The estimated repair cost for addressing the F22 fault could range from £150 to £300, depending on whether the issue is simply a pressure adjustment or if a component like a pressure relief valve needs replacement.