In plain English
Think of the house as having one “brain” that connects lots of different smart devices. You normally interact with it by speaking to Alexa.
Most of the time: just use Alexa and everything works. The rest of the system is mainly there so different device brands can behave as one home.
The key parts
- Home Assistant — the brain (runs in the house).
- Alexa — the voice interface (what you talk to).
- Device systems — how different brands connect (Zigbee, Meross, Tuya, SmartThings, Broadlink).
The systems we use
You don’t need to memorise these. They mainly help when troubleshooting (e.g. “is this a Wi-Fi plug or a Zigbee light?”).
Controls Zigbee devices such as many bulbs and switches (and some locks). This is usually the most reliable part of the system.
- If a Zigbee light doesn’t respond, it’s usually power to the device, or the Zigbee network being busy.
- These devices do not depend on the internet.
Used for some smart plugs and extension leads. These use Wi-Fi, and may depend on internet/service availability.
- If a plug doesn’t respond, it’s often Wi-Fi or the Meross service.
- Power-cycling the plug can help (unplug for 10 seconds).
Some Tuya devices are controlled locally (inside the house) without relying heavily on the cloud.
- Usually stable once set up.
- If it fails, it can be Wi-Fi or the device “dropping off” the network.
Some devices are linked via SmartThings. This is cloud-based and can be affected by internet/service issues.
- If a SmartThings device fails, check if other SmartThings devices also fail.
- Sometimes it fixes itself after a few minutes.
Used for RF-controlled items like candles. It “sends a remote control signal” rather than talking to a smart device.
- If the candle doesn’t respond, it may be distance/line-of-sight, or the candle batteries.
- RF devices aren’t “confirmed” — they might miss a command occasionally.
Alexa is how most people control the home. Alexa talks to Home Assistant behind the scenes.
- If Alexa says “device not responding”, check Troubleshooting.
- Sometimes repeating the command once works.
Home Assistant links everything together and runs automations (like dusk lighting and late-night behaviour).
- If lots of things fail at once, Home Assistant or the internet may be down.
- Most of the time, it runs quietly in the background.
Important: Some devices are local (work even if the internet is down), and some are cloud-based. That’s why sometimes “one thing stops working” while everything else is fine.