📋 Key Takeaways

  • 1.What it means: System pressure has dropped below the minimum operating level.
  • 2.What to do: Repressurise to 1–1.5 bar then reset.
  • 3.DIY or engineer? You can try one reset after addressing the cause. If it returns, call a Gas Safe engineer.
🔒Written by a Gas Safe registered engineer
Glow-wormEnergy 18/25/30 Combi

Fault Code F.22: Low water pressure

System pressure has dropped below the minimum operating level.

What to do: Repressurise to 1–1.5 bar then reset.
🔄 You can try resetting

This fault code can often be cleared by addressing the underlying issue (e.g. repressurising) and pressing the reset button once. If the fault returns after one reset, do not keep resetting — call a Gas Safe engineer to investigate.

🔐

Full Technical Repair Guide — Pro Members

The component-level repair guide for this fault code is available to Pro subscribers — designed for Gas Safe engineers and heating professionals.

  • Exact components to test and replace
  • Pressure and temperature diagnostic values
  • Common misdiagnosis warnings
  • Printable fault diagnosis sheet
  • Direct links to genuine spare parts
Register Interest — Pro Access

📞 Get Help Directly

📄
Glow-worm Energy 18/25/30 Combi — Official Manual
Installation & user guide from the manufacturer
Download ↗
Glow-worm Support
📞 0330 100 3461
Support page ↗
Gas Safe Register
🔧 Find an engineer
gassaferegister.co.uk ↗
Gas Emergency
🚨 0800 111 999
Free, 24/7 — if you smell gas

Phone numbers provided in good faith — verify on the manufacturer's official website. PlumbingAdvice.co.uk is not affiliated with any boiler manufacturer.

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