vSMART app shows no hot water demand or hot water remains cold despite schedule being active.

Steps to check hot water control:

• Verify DHW schedule: In the app, open the domestic hot water schedule and ensure there are ON periods with a reasonable target temperature.
• Check DHW mode: Confirm that hot water control is enabled in system configuration and that the correct cylinder type is selected (if applicable).
• Manual boost: Use the app's hot water boost function (if available) to force a demand and see if the boiler responds.
• Check boiler display: Look at the boiler's own display to see if it indicates a hot water demand or any DHW‑related error codes.

If the vSMART shows demand but the cylinder does not heat, the issue may be with the cylinder sensor, motorized valve, or boiler DHW controls, which should be checked by a qualified heating engineer.