No domestic hot water, but heating works normally

Safety: Hot water circuits can be very hot. Allow components to cool before handling.

• Check DHW demand: Open a hot tap fully and observe the boiler. It should recognise demand and start.
• Observe boiler display: If no DHW symbol appears, the flow sensor may not be detecting flow.
• Check cold inlet filter (competent person): Some boilers have a filter on the cold water inlet; if blocked, flow may be insufficient to trigger DHW.
• Technician tasks: A professional will test and replace the DHW flow sensor, diverter valve motor or cartridge, and descale or replace the plate heat exchanger if blocked.