WC + independant zone valve

[Mr Blobby]

So this month is heat pump month, and I am seriously excited about it.  The challenge will be, however, to convince our builder and plumber not to hand over total control of the ASHP install to a third party installer.  Thanks to the useful guidance on this forum and the low heat demand in our house, I am keen to run WC mode without any buffer tank or additional pumps if possible.  I suspect the third party installer would prefer a more expensive, less efficient design.  I will soon find out.

 

We have two UFH manifolds, GF and FF.  It would be nice to treat the FF manifold as a seperate zone.  The GF zone will always be open and should have enough volume to satisfy the flow requirement of the pump. 

 

The panasonic text book provides a direct (no buffer) 2-zone implementation but requires flow temp sensors on both zones and valves on each zone, all connected back to an additinal circuit board in the ASHP.  I'm not convinced it needs to be that complicated and chat gpt concurs.

 

I think there is a far simpler solution, to configure the system as a single zone, bog standard WC implementation, but then install a two port valve before the FF manifold connected directly to a thermostat on the first floor.  This would provide a way of isolating the zone altogether.  The heat pump would not need to know about this seperate zone.  A thermostat with cooling function seems to be available that would cool down to cooling setpoint so, when the heatpump is set to cooling mode, then the FF thermostat would also be able to open the zone valve to the FF if the FF is overheating.

 

The simplicity and low cost of this design appeals greatly.  No additional flow temp sensors, one zone valve, no additional circuit board.  What's not to like?

 

Is this standard stuff, do others on this forum control zones like this, perhaps to switch fancoils in/out, with an indepentant thermostat/relay/valvethat is wholly independant of the ASHP?  Or is is bonkers?

 

 

(The more complicated, integrated panasonic implementation is in the attached pdf)

 

 

 Direct two zone third party controls 5kW 7kW 9kW.pdf

Edited 4 hours ago by Mr Blobby