Choose one noticeable problem
Leaks under the sink, awkward hallway lighting or an overheated bedroom are reasons to start with a specific outcome.
Account for the whole system
Besides a sensor, you may need a controller, actuator and power. Compare the cost of a working solution, not just one component.
Leave room to expand
Discuss future needs so the first purchase fits the chosen architecture. You do not need every function immediately.
Example starter kits
Leak protection: SONOFF SNZB-05P sensors and a ZBBridge-U gateway report water; automatic shutoff needs a separate motorised valve. Room-by-room heating: SONOFF TRVZB radiator heads with a compatible Zigbee gateway, such as the same ZBBridge-U. The gateway needs constant power and a connection to your home network.
What happens without power or internet
Find out in advance what keeps working during outages. Without internet, remote access and cloud commands stop; routines run by the hub or Home Assistant server itself can work locally — check this for your specific system. Without power, the gateway and router switch off unless they have backup power. For leak protection, discuss a UPS for the gateway and router and how the valve behaves when power is lost.
What counts as a working first stage?
Write down one sequence: what happens, what the home should do and how you will know it worked. For leaks, discuss sensor positions, valve access, power and confirmation of closure. At handover, test the agreed routine rather than merely checking that the sensor appears in an app.
Official sources and scope
This is the platforms’ official documentation; we check the compatibility of a specific model separately.
From the principle to the exact model
The sensor alone cannot stop water. We check plumbing, the actuator, power, local communication and manual control. Phone alerts usually need internet.
