Boiler provides central heating but no domestic hot water (on combi models).

How to Fix / Troubleshooting

Safety: Hot water circuits can become very hot; isolate power and water before disassembly.

User checks:

Check that cold water supply to the boiler is on and that other cold taps work.
Run a hot tap fully open and observe if the boiler attempts to fire.

Engineer checks:

Test the DHW flow sensor/turbine on the EHC combi boiler; clean or replace if not detecting flow.
Inspect and clean the plate heat exchanger if blocked by scale or sludge.
Check diverter valve movement and replace actuator or cartridge if stuck.
Verify DHW NTC sensor readings.

After repair, test multiple hot water outlets to confirm stable temperature and flow.