What does the Worcester Bosch Greenstar Si F24 fault code mean?
The F24 fault code on the Worcester Bosch Greenstar Si indicates an overheating issue within the boiler. This typically occurs when the boiler’s temperature exceeds safe operating limits, triggering a safety mechanism to prevent damage.
Common Causes
- Blocked Heat Exchanger: A buildup of debris or limescale can restrict water flow, causing the boiler to overheat.
- Faulty Thermostat: If the thermostat is malfunctioning, it may not accurately regulate the boiler’s temperature, leading to overheating.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer for this issue, as overheating can be dangerous and may involve gas or electrical components that require professional handling.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F24 fault could range around £150 to £300, depending on whether a heat exchanger cleaning or thermostat replacement is needed. This estimate reflects the cost of parts and labour for a qualified engineer.