Zigbee range woes - move to wifi?

Hi hass enthusiasts,

I’m setting up hass and I have decided to go with Zigbee devices. I have a Sonoff sensor in every room along with some mains plugs throughout my flat. Setup was really easy. Kudos to the developers :slight_smile:

What I want to achieve: I want to get a notification when my washing machine (in the basement) is finished.

I had this working before with a wifi plug with power metering (TP-Link HS110), but I wanted to standardize on Zigbee due to the built-in mesh feature. The HS110 in the basement would occasionally lose connection and become “unavailable” for periods of time.

Now, I replaced the HS110 with a Tuya plug (_TZ3000_gjnozsaz TS011F) - and I get no reception at all! I have access to a separate room in the basement which is closer to my flat. I decided to install another mains plug there to act as a repeater, but also that plug could not pair.

As soon as I move these plugs to my flat on the ground floor, they pair immediately. From this observation, I believe that Zigbee range is much worse than for my Wifi based devices.

Let me sum up my setup again:

  • Conbee II stick
  • hass OS running on a RPI 4
  • Zigbee mesh running in my flat in the ground floor
  • Washing machine is in the basement, somewhat remote from my flat
  • Reinforced concrete between the two floors
  • I have access to a power outlet in the basement which resides directly under my office room
    • This room has reasonable wifi reception
    • I could probably also connect to my home network via Powerline from that outlet

I think I have the following options

a) Put a separate zigbee coordinator in the basement and either connect via wifi or powerline
b) Find some powerful zigbee extender, if such a thing exists?
c) Put a wifi range extender in the basement
d) Try a different wifi plug. Perhaps a shelly would be better?

What do the more experienced people in the community think?

I have observed that the repeater/router function does not work if the wiring for that location does not include a neutral wire. (sometimes it happens when the electrician/owner doesn’t follow code).

70 to 100 meters is what the spec says.

In reality it’s about half that because walls, floors, wires, pipes, etc. are a thing - and it’ll be even worse going through floors as they usually also carry the big infrastructure for your house. When I planned out my own Zwave and Zigbee infrastructures I made sure there was a repeater every 40-60 feet, let’s call it 20m. Overkill, probably - but, I ALSO don’t have any signal drops - ever.

How do I know when I have a strong enough mesh?
If you cannot join your device in place - you don’t have enough repeaters.

Realistically you should probably be ok if you can get a repeater every 25-50 meters between your coordinator and that device and have fewer than four hops between the device and the coordinator. You said remote? Can that be done?

Do you have your Conbee on a USB extension cable to avoid interference? You might be better off with a co-ordinator that has an external antenna. I’m assuming you can’t put repeaters in all the rooms between your flat and the basement, because they’re not all yours.

If you’re in an apartment building, the basement and your flat might be on different power networks, in which case a powerline wifi extender won’t work.

I have about 6 TP-Link power plugs, all well within wifi range that regularly go unavailable for a few minutes. I think the issue is the product and/or the integration, not the wifi.

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Concrete floors are a real problem, especially in larger buildings. They’re full of rebar and sometimes are poured over corrugated sheet metal (think: Faraday cage.) Same for concrete walls. Other walls and infrastructure (wires, ducts) also interfere with the signal.

On the other side of the equation you have interference. Assuming lots of other flats, everyone will have their own WiFi router, using all the available channels. Zigbee uses the same general segment of the spectrum as WiFi. It does seem like some WiFi devices can withstand interference better than some Zigbee devices. Yours are probably always struggling, and when you see them “unavailable” they’ve just reached some limit.

I personally like Zigbee, but in a crowded WiFi environment I might consider Z-Wave, as it uses a different part of the spectrum. My HUSBZB-1 does both Zigbee and Z-Wave. I’m not sure if your Conbee II does the same. If so it might be worth making an exception to your “all Zigbee” rule for that one sensor.

One final point: In an environment with lots of WiFi routers, when the power goes out, they all try to find the best channel to use when they boot back up. Even if a neighbor reboots their router for some reason. it may pick a different channel than before. Interference on any given channel can change suddenly.

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I have a very similar HW setup and experienced a similar issue with range. I had several outdoor Zigbee devices that would intermittently drop off. I was able to improve signal to two of the devices by adding a zigbee plug somewhere between them and the house, but I still had the occasional drop.
Like you, I was using the zigbee plug to track power usage of a portable A/C unit in a separate workshop in my property.
Ultimately, the only reliable solution was WiFi. I am using Sonoff S31TPB(US) plugs for switching/power metering and Sonoff BASICR2 for plain switching. All local (no cloud) using Sonoff LAN custom component.

BTW, in addition to the 30 zigbee devices, I also have 57 Zwave devices and the range is not any better than Zigbee.

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Yes, I do have an extension cable!

You are right. I would also be afraid that introducing another powerline connector would negatively impact the existing setup I have.

That’s a great point. I will set up some ping monitoring for the HS110.

Your point on interference is also spot on. Concrete, steel, other wifi’s and perhaps the neighbor’s microwave oven might make life hard for my poor little HS110.

What I am trying now: I managed to pick up a used wifi repeater for 15€ and I will put that in the basement. Link quality seems reasonable for now and I think it will help a lot with improving the signal for the HS110 sitting in a different room in the basement.

I’m a bit sad not to use Zigbee here because it means I cannot put any other Zigbee devices in my basement. In reality, the only relevant sensor would be power meter monitoring. But my power meter is so old that there is no digital interface, so the point is moot :slight_smile:

Short of adding more mains-powered Zigbee units (not possible for me), wifi seems to be the best option for now. It also shows the strengths of home assistant: zigbee not working? Just use wifi!

One option that I might explore in the future is a wifi-connected Zigbee coordinator, such as the SONOFF ZBBridge. However, the official HASS documentation warns against using that one because the protocol is not stable over wifi.

Thanks for the feedback. I hope WiFi (and the additional repeater) would solve my issue.

WiFi also has the advantage that plugs with power metering are a bit easier to find.

@Zoriontsu @CaptTom Since you both have Zigbee and z-wave, I would like to ask: which one do you prefer? Any particular strengths/weaknesses?

I’m glad you’ve found a solution you’re happy with.

For the record, Zigbee uses the same part of the spectrum as WiFi, so it would be sensitive to the same interference and penetration problems. At least with a WiFi router it’s easier to change channels to try to get around changing interference from surrounding systems. It’s also possible that the individual device is more tolerant of instability. The final “fix” might be different for other environments and use cases.

I have been doing home automation since the X10 days (just dated myself :grin:). I started with ZWave and expanded to Zigbee when the type of devices I needed were not available w/Zwave.
I use WiFi devices only to address range constraints.
Many pros and cons for both, but nowadays for me it boils down to this:
ZWave:
Pros: Network Reliability
Cons: Ridiculous price for some simple devices
Zigbee:
Pros: Affordable, widely available devices
Cons: ZigBee and Wi-Fi Coexistence in the 2.4 GHz band can (and at some point will) cause conflict.

In my large (and obsessively ever growing ) mixed environment, I addressed the 2.4 GHz conflicts when I migrated my WiFi network to Ubiquiti Unifi several years ago. Unifi aggressively scans and adjusts channels to avoid conflict.

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