Boiler displays E14, burner does not start, and there may be no response to hot water demand.

Safety first: Turn off power and close the cold water inlet before removing any DHW components. Expect water spillage when opening the DHW circuit.

Step-by-step checks:

• 1. Confirm symptom: Open a hot tap fully. If the boiler does not start and E14 appears, the boiler is not detecting flow.
• 2. Clean inlet filter: Many Viadrus combi boilers have a small filter at the cold water inlet. Isolate the cold feed, remove the filter, and clean any debris or scale.
• 3. Inspect flow sensor: Locate the DHW flow switch or turbine sensor. Check for obvious damage or loose wiring. On turbine types, remove and rinse under running water to clear debris.
• 4. Reset and test: Reassemble, open the cold inlet, check for leaks, then restore power and test hot water again.

When to stop: If E14 persists, the flow sensor may need replacement or the PCB input may be faulty. This should be handled by a professional.