Domestic hot water temperature fluctuates between hot and cold during use

Safety first: Turn off power and close water isolation valves before removing any DHW components.

• Check flow rate: Ensure taps are opened sufficiently to maintain the minimum flow required by the Roca combi furnace.
• Clean inlet filters: Remove and clean any cold water inlet filters or strainers to the boiler.
• Inspect DHW sensor: Verify the DHW NTC sensor is firmly attached and wiring is intact.
• Descale plate exchanger (professional): If limescale is suspected (common in hard water areas), have the DHW plate heat exchanger chemically descaled or replaced.

Warning: DHW circuits are potable water; use only approved descaling methods and materials.