Boiler produces hot water but no central heating.

Safety: Isolate power before removing boiler covers.

• Check valves: Confirm that the heating flow and return isolation valves under the boiler are fully open.
• Verify controller settings: Ensure heating mode is enabled and the schedule allows heating on the Klimosz controller.
• Test thermostat: Raise the room thermostat setting and listen for a click or check for a call-for-heat symbol on the display.
• Inspect diverter valve: Observe whether the diverter motor moves when switching between DHW and heating. If it remains in DHW position, the valve or actuator may need replacement.