Noisy operation from Gledhill water heater, including humming, banging, or gurgling sounds

Safety: Some components and pipes may be hot. Allow to cool where possible and use gloves.

Steps:

• Bleed air: Use automatic or manual air vents on the primary circuit and bleed radiators to remove trapped air. Run the system and re‑bleed if necessary.
• Adjust pump speed: If the circulation pump has multiple speed settings, try reducing the speed to the recommended level to minimise noise and turbulence.
• Check pipe supports: Inspect visible pipework around the Gledhill unit. Secure any loose pipes with appropriate clips to prevent banging when valves open/close.
• Descale: Kettling or boiling noises from immersions or heat exchangers often indicate scale. A professional can descale or replace affected components.

Note: Sudden loud banging (water hammer) may require installation of water hammer arrestors or adjustment of valve closing speeds.