Worcester,
I'm trying to ensure the most efficient blending of supply to UFH from the accumulator as possible.
I've 1000ltr akvaterm solar plus accumulator tank
stove with back boiler 16kw( still only getting 8-10kw) Broseley evo 26 to accumulator through laddomat
40 evacuated joule tubes Connect via Laddomat 11-21
house 193m2 all underfloor heating from bottom of acc tank manifold Robot with TRV
high levels of insulation all elements U values 0.12, window triple glazed U value 0.7
'Beam' heat recovery unit, building airtightness around 2
immersion for accumulator still to be fitted.
problem I'm having is I've set the lowest setting on TRV (20 degrees) but supply temp on manifold thermometer is 35-40. Before I set it at 20 the supply temp was off the gauge and worried might damage screed. I could have anything from 40-85 degrees in bottom of tank
Half the house is large open plan dinning, kitchen and living, never needed underfloor on as if cold stove is lit, also utility room has accumulator tank so again no need for heating on. Heat only needed for hall and bedrooms. All rooms controlled by heatmiser stats, all set at 20 degrees, only underfloor heating in hall and bedrooms ever comes on that all I need.
in this good weather the bedroom thermostats would usually drop to 19 degrees in early morning, but I've turned the thermostat on acc tank to 70 so the underfloor will not start, by lunch time the room temps are back up to 20, maybe by passive solar or heat recovery?
I've attached photo of manifold. From manifold to tank, It has it's own pump, TRV, then second pump, myson, then manual 4 way valve joining top, middle and bottom of tank. No idea what it does.
the accumulator tank has 3 manual dial stats, bottom for dumping heat into hall floor screed, middle to set temp for underfloor to come on, and another stat at top of tank to control solar, however I don't know how it is set and neither does guy who designed system.
everything was 'commissioned' back in November, just immersion to fit, all money paid up,plumber his electrician all just very busy, but I'm hoping they will be back on Friday for at least to fit the immersion.
How would you rate the 'Robot' manifold? My only annoyance is they priced and I paid for a manifold with flow meters which I didn't get, but I believe the Robot is self balancing, looks like a robust unit though, do you really need flow meters?
plumber also getting me a price for another 20 SOlar tubes, even in this great weather the panels are pumping at 70-80 degrees, but still a deficit for the next day. if I could only get the system to heat the top section of the tank then the existing set up would be fine, at the moment the whole tanks is being heated and all I need is DHW during this good spell.
That's controlled by the stats on the manifold, the main mixing valve should be set up to match the design flow temperature of the ufh installtion, and not touched 
