Smart thermostat shows E07 and cannot detect or control the hot water circuit.

Safety warning: Hot water controls may involve mains voltage. Turn off power to the boiler and wiring center before touching any wiring.

• Confirm system type: In the Tado app, verify that your system is configured as a system boiler with separate hot water control, not as a combi boiler.
• Check Extension Kit wiring: At the Tado Extension Kit or wiring center, confirm that the hot water ON terminal is wired to the correct input on the boiler or motorized valve, following Tado’s wiring diagram.
• Verify cylinder thermostat: Ensure the existing cylinder thermostat is correctly wired in series with the Tado hot water call, not bypassed or disconnected.
• Test manual override: If your wiring center has a manual hot water switch, test if the boiler and cylinder respond. If not, the issue may be with the boiler or valve, not Tado.
• Restore power and test: After confirming wiring, restore power and request hot water via the app. If E07 persists, the hot water relay on the Extension Kit may be faulty.