It depends on how you want it to work, I am using Drayton Wiser, which is basic same connections
you can have with Wiser I seem to remember up to 9 thermostats per channel, the two channel is designed for DHW and CH, to get two hard-wired zones with CH it needs the three channel version. In my home we have a main house, and a flat, so it would be a good idea to have the flat and the main house on hard-wired zone valves.
But within the main house, the TRV heads do the same as a hard-wired motorised valve, but allow gradually closing and opening rather than all or nothing as with a hard-wired motorised valve, and the way the boiler works, it wants the demand to slowly increase and decrease, not to be all or nothing, so unless using an old oil boiler which does not modulate, and capture the latent heat from flue gasses, the control needs to be as much as possible by the TRV heads, not any hard-wired motorised valve.
Even with my oil fired boiler, the use of TRV heads is far better as to using hard-wired zone valves, I say hard-wired, as the TRV's are zone valves, all mine are programmable, but only one is linked to the main hub.
My guess is these two
need linking together, so both the old zone valves work together. But without testing, can't be sure. I am not sure, I did the right thing using the TRV head to turn the heating on/off, I assume Hive is the same as Wiser, and you can have multi-devices connected to one channel, to trigger the boiler, I have three devices, two wall thermostats and one TRV head.
The Wiser, in theory you don't need any wall thermostats, the TRV heads can turn the heating on/off, however it is down to where the radiators are, a radiator against an internal wall when heating not running will reasonably monitor the room temperature, and once the heating is running it is ideally placed to measure whole room temperature. However, against an external wall, it tends to be cooler than the general room temperature, so can fire the heating when not really required.
I made an error with wife's bedroom using a linked TRV head, would have been better with a wall thermostat, but they both connect to hub wireless, so makes no difference wiring wise.
The connection to OpenTherm does change between Hive and Wiser, as to where the connections are made, but I assume you're not using the OpenTherm option. So basically the fewer times the hub switches boiler on/off the better. The TRV's control room temperature, and doing so they regulated the water flow, as they close the by-pass valve opens, and as warmer water returns to the boiler, the boiler reduces output, each time the boiler is switched off, and back on again, it has to adjust the output from scratch again, so any on/off zone valves cause the boiler not to work as efficient as it could do.
There is a thread at
https://www.diynot.com/diy/threads/replacing-honeywell-with-hive.648171/page-2#post-6055385 which seems to be about the same problem.
When I came to do my central heating I employed a plumber to do the plumbing work, had not expected him to continue with two pumps, but by the time I found out, too late. So I was left with the original programmer,
and I had to consider what to do, the thermostat
never did find the wireless unit, only the receiver, and when testing the cables, the three core only had two cores working, so I decided best was to label what when where and start from scratch.
