Two boilers, single control unit – possible?

[gorbacheff]

Hi guys,

I own a house that's been divided in two completely separate properties, years ago. Since then, there are two completely independent heating circuits (floor 1; floor 2+3), each one has its own boiler, linked to a respective Honeywell Chronoterm IV head unit (two units at home, in total). We've made the property united again, and I am in search for a smart heating solution that would cover the whole house.
Evohome offer sounds great but I don't want to mess around with two central controllers. I wonder if it is technically possible to have a single central controller for two boilers? I'd want it that way: for rooms 1 and 2, the central controller sends the signal to boiler A, for rooms 3, 4, 5 the signal is sent to boiler B.
My educated guess is "no", sill, maybe there are any workarounds? Then, what solution I should stick to? Some DIY possible if necessary.

Thanks,
Max

[top brake]

Evohome does not support this application

You'll need an evohome controller for each boiler

[slippyr4]

such a shame. if only you could add multiple relays and for each zone, configure which relay needs to be operated, then you'd have a lot more flexibility for twin boiler setups, and S-plan plus too.

[Richard]

Figure 4 schematic replaces S Plan plus? Why are you suggesting S Plan Plus is not possible?

What is the issue with having 2x evohome Controllers? Many flats are like this and for an additional £200 you would have full and correct control of both boilers. From the Honeywell App side, it is literally a 2x button press to change between evohome Controllers and many properties with more than 12x zones end up going down this route. My own home has 2x evohome Controllers and there is really no issue.

[slippyr4]

But for what is shown in figure 4 you have to either lock open the zone valves or remove them entirely., which obviously works. But if they supported what I suggested then you could do S plan plus conversions with no wet work, and many multi boiler setups.

[Richard]

S Plan Plus is multiple heating motorised zone valves on a heating system. You said evohome does not support this application, which it does on a single zone basis (if you used Y87RF2024 bound through evohome as a 'Zone Valve' zone).

Figure 4 is the perfect situation with evohome when using HR92 Radiator Controllers. Zone Valves, S Plan, S Plan Plus & Y Plan are unique to UK/US market only and not used in Europe.