How to fix Glow-worm Energy fault code F53

What does the Glow-worm Energy F53 fault code mean?

The F53 fault code indicates a domestic hot water (DHW) pressure fault in the Glow-worm Energy boiler. This typically means that the boiler is unable to maintain the required pressure for hot water delivery, which can lead to inadequate heating performance.

Common Causes

  • Low Water Pressure: Insufficient water pressure in the system can trigger this fault, often due to leaks or insufficient filling.
  • Faulty Pressure Sensor: A malfunctioning pressure sensor may incorrectly report the water pressure, causing the boiler to shut down.

Can I fix it myself? (DIY)

If you are comfortable, you can check the pressure gauge on the boiler and attempt to refill the system if the pressure is low (typically below 1 bar). However, if you suspect a faulty sensor or if the issue persists, it is strongly advised to call a Gas Safe Engineer for further diagnosis and repair.

Estimated Repair Cost (2026 UK Prices)

The estimated repair cost for addressing the F53 fault could range from £150 to £250, primarily depending on whether a pressure sensor needs replacement or if a simple refill is sufficient. This estimate includes parts and labour for a qualified engineer.