Things to bear in mind:
- The ZHA map shows all possible routes, not just the ones in use. There usually is a fair amount of orange and red.
- Zigbee is designed to be a bit of a black box, and messages will pick their own routes “automagically”. As @eamonn says, if devices are working, don’t worry about it.
- An extra router never hurts!
There’s an explanation of what the map colours mean, along with a diagram of how Zigbee channels map onto wi-fi channels here:
Not many people know that... A random collection of Zigbee trivia
Yes, it is 2.4 you should be looking at.
A good way of finding out how busy your channels are is to download diagnostics from the ZHA integration page.
Somewhere near the end of a very long file you will find something like:
"energy_scan": {
"11": 68.14622793558128,
"12": 75.96022321405563,
"13": 70.89933442360993,
"14": 39.90320178295578,
"15": 96.64469941013013,
"16": 4.69985354430736,
"17": 8.631361812931262,
"18": 8.631361812931262,
"19": 4.69985354430736,
"20": 80.38447947821754,
"21": 80.38447947821754,
"22": 92.0598007161209,
"23": 93.76433891498253,
"24": 85.82097888710312,
"25": 4.69985354430736,
"26": 97.39286236923465
},
The numbers are percentages and give you an idea of the amount of noise on each Zigbee channel, including Zigbee traffic, wi-fi and anything else that’s going on. In the example above, my Zigbee is on channel 20 and perfectly stable, even though the number is quite high.