Water hammer or banging noise in pipes when heater heats or when taps are closed.

Safety: Sudden pressure surges can stress plumbing and the heater. Address promptly.

Steps:

• Check pressure: Measure mains pressure. If high, install a pressure reducing valve on the supply.
• Install arrestors: Fit water hammer arrestors near quick-closing valves (e.g., mixer taps, washing machines).
• Secure pipes: Ensure hot and cold pipes near the Eldom heater are properly clipped and not free to bang against walls.