Heatmiser, Hive and Willis....Help!

[Antonb182]

OK, so i'm adding wet UFH to our outbuilding, slab and pipes are in, manifold is set up and i'm now at the stage of getting it up and running, but I have some questions, which while not insurmountable, I'd definitely benefit from some more sensible/learned opinions on.

 

First one is the Willis. I'm planning on using it to heat two relatively small spaces (approx 25sqm each)  and i'd be super surprised if they ever both needed heating at the same time, so I think i'm going to be OK with a single Willis. However, what i've not figured out, is how people are switching them on/off depending on the system needs. As far as I understand, there's no switched live on the unit, so I assume i'd need a relay/switch of sorts between the (always on) spur and the unit. Is this what people generally do? If not, how are you guys controlling the on off of the Willis?  Not sure if it makes a difference, but the whole thing is going to be controlled via the heatmiser UH4. 

 

Secondly, because I already have them, I was planning on using Hive to control the two rooms in two separate zones. Which in my mind, makes perfect sense, one receiver and one thermostat for each zone. Has anyone else done this already and how did it go? I still have the possibility to switch to something more easily integrated, but i'd definitely rather use something I already have. 

[JohnMo]

To me you don't want Willis on without pump on. So drive a suitably rated multi pin relay from pump switch in wiring centre. Drive and Willis from relay. How you control zones doesn't matter after that. Your flow temperature will be by inbuilt thermostat, but add overheat protection with a pipe stat downstream of Willis interlocked to pump Willis power. So mains to pipe stat, then relay, input. So if pipe too hot Willis is off.