What does the Worcester Bosch Greenstar Si F22 fault code mean?
The F22 fault code indicates a dry fire condition or low pressure within the system. This typically means that the boiler is unable to detect sufficient water pressure to operate safely.
Common Causes
- Low Water Pressure: This can occur due to leaks in the system or insufficient water supply.
- Air in the System: Trapped air can prevent proper water circulation, leading to low pressure and triggering the fault code.
Can I fix it myself? (DIY)
You can attempt to fix low pressure by checking the pressure gauge and re-pressurising the system if it is below 1 bar. However, if the issue persists or if you suspect a gas or electrical fault, it is essential to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F22 fault could be around £150 to £250, primarily depending on whether a simple re-pressurisation is needed or if there are underlying issues such as leaks that require more extensive repairs.