Multizone with Rads, Underfloor & DHW - which controller

[gorty]

I'm planning a totally new heating systems, every component new. I've got a rough idea of what I want from the system. Looking around the manufacturers websites I'm a bit lost as to the best controls to specify for my needs, initially I looked at Valliant but they only offer 2-zones max. I figure my system needs simplified a bit, see attached diagram, I'll have 2 showers and I want a high flow rate 18L/min hence the 300L tank.

Ideally I'd like to program on/off times for each zone denoted by the zone valves. I'd also like to program individual on/off times for each underfloor loop, is this possible?

What controls would you recommend?

20110110 System

• gorty
• 11 Jan 2011
• 1

proposed zoning/controls

 

[Wangerman]

A programmable trend controller or BMS system would do the job but do not come cheap.

They have multi zonal output and are fully configurable via a pc link

 

[sparkiedave]

I'd put individual programable thermostats on each zone so you can set times/temperatures for each zone, UF heating manifolds can be bought with actuator valves for each zone, you may find the UF heating works more efficiently by being on longer as, when it comes on from cold it takes longer to warm up the room than a radiator would, but then the slab retains the heat for longer, also, if you have a TRV on the bathroom rad, make sure your boiler has an integrated bypass valve

 

[Norcon]

Do parts of the house have both ufh and radiators?

 

[gorty]

Thanks, had a look at Trend, I don't want to got nuts and start controlling my heating from a laptop or touchscreen, it's a 3-bed semi with underfloor on the ground floor and upstairs bathroom. Maybe a combination of two domestic controllers would work? I'll talk to some underfloor installers, see how they connect up with exisiting wet systems. My diagram probably has too many zone valves, it mainly to convey how I expect to control each area individually. In spring/autumn the underfloor will be left off most of the time.

 

[tomsmithers]

I am thinking of designing a new central heating / hot water system very similar to the one shown in the diagram at the top of this thread but the one problem I have is how to deal with the pump over-run facility on my boiler. When all of the heating and HW controls are switched off the return path to the boiler will be blocked as all of the 2 port valves will be sprung shut. Should I therefore install an auto bypass valve to compensate for this or is there any way of opening the last used circuit to dissipate the remaining heat in the boiler? I suppose the other option is to have a heated towel rail without a control valve so that this part of the circuit will always be open to allow the pump over-run.

Any help would be much appreciated. Thanks

 

[D_Hailsham]

Should I therefore install an auto bypass valve to compensate for this

That's the purpose of the ABV!

PS You shouldn't hijack another thread.