What does the Glow-worm Ultimate F88 fault code mean?
The F88 fault code on the Glow-worm Ultimate indicates a problem with the domestic hot water (DHW) pump, which may not be operating correctly. This can lead to insufficient hot water supply and requires immediate attention to ensure proper functioning of the boiler.
Common Causes
- Blocked DHW Pump: Debris or scale buildup can obstruct the pump, preventing it from circulating water effectively.
- Electrical Fault: Issues with the wiring or connections to the DHW pump can disrupt its operation, leading to the fault code being triggered.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer for this issue, as it involves electrical components and potential gas safety risks. Attempting to fix it yourself could lead to further complications or safety hazards.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F88 fault could be around £150 to £250, depending on whether the DHW pump needs cleaning, repair, or replacement. This cost reflects the complexity of the work and the need for a qualified technician.