@harriup I don't have the little box.  The house is detached.  House built on a slope (where I live very hilly!) - back garden was reached by steps from house - we had a wooden deck - this was replaced and we excavated the back back garden and the new part "hugs" the house at a lower level.  There is then a terrace on top (lots of insulation) - it goes out by 4 metres and stretches the width of the house - about 13 metres and the accommodation in question is under this.

This is my new settings and pictures of each controller and also the electricity used so far today.  Yesterday I used 18kWh and today the weather is similar - so a good experiment

OK - so 24 hours later and all zones are showing 16 degrees - including the (what was) frost setting bathroom - which hasn't seen that since the summer and solar gain/warmer temp generally!  I used 28kwh of electricity yesterday - so 10 more than previous day (both days about the same outside temp all day) - I guess this could be to get up to desired temp?  I will leave like this another 24 hours as tonight the temp outside will be -1 or -2

PS It took most of the day for the temp in bathroom and bedroom - at 19:30 last night - 10 hours after I increased the temp for each controller, the bathroom was still showing 15 degrees.  

OK - another 24 hours of my experiment:

usage yesterday: 18 kwh

so far today 12 kWh (I'm recording usage at same time each day)

overnight temp outside about -2 (quite a bit colder than last couple of days)

All zones have maintained 15 degrees - I will leave it like this for the bedroom and bathroom zone

In the living area zone, I have upped temperature from 15 to 17 - it will be interesting to see how long it takes to get up to temp.  

OK day 4 of experiment - outside temp today cold - it's 09:00 and still about -1 and overnight up to -3

usage so far - 14kwh

usage yesterday 32 kWh - yesterday I upped the living room temp to 17 (currently it's on 14 and setting is for 16 in that room today)

The bedroom and bathroom zone have maintained 15 degrees 

Posted by: @sarah

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OK day 4 of experiment - outside temp today cold - it's 09:00 and still about -1 and overnight up to -3

usage so far - 14kwh

usage yesterday 32 kWh - yesterday I upped the living room temp to 17 (currently it's on 14 and setting is for 16 in that room today)

The bedroom and bathroom zone have maintained 15 degrees 

@Sarah,

Thanks for the update.  I am a bit puzzled about two things.

Firstly, why isn't a 40 degree flow with your ufh heating your space?  That's quite hot for ufh. There are lots of reasons it might not:

- high heat loss (unlikely for a new build)

- poor flow rate/blocked ufh pipes

- it's not really 40 degrees flow temperature

- the heat is being lost somewhere, e.g. the ufh is emitting heat downwards into the floor and not through the floor covering into the rooms.

Secondly, why is 40 degree flow in a 60 m2 space using so much energy?  My Ecodan ASHP heats 15 radiators at around 40 degrees that keep a 170 m2 house at 21 degrees with only a little more energy used than you.  My usage for heating and HW  yesterday (and that included a bath for the dog!) was 37kWh.

After today, it will be worth checking the flow rate of the ASHP and the temperature of the flow.  You'll need some sort of thermometer for the flow temp (there are some cheap aquarium ones on Amazon that work well).  For the flow rate you need to get into the engineer's menu on the controller, which is very straightforward. Let me know if you want to do this. 

I don't have any experience of ufh.  Do you have any details about the system - volume, pipe spacing and diameter, depth, floor insulation, type of tiles, etc.?  Someone who knows about ufh might be able to advise.

Hi Sarah,

Can you provide photo's, both wide angle and close up of your UFH manifold?

And while you're on the photography assignment!! a pic or two of the energy screens, particularly the one that shows totals for the past month and year on the controller would be useful. You've told us how much energy you are inputting to the system but I don't think we know how much the system is outputting. This might give an idea whether the heat is being generated inefficiently or being lost somewhere on the way.

OK - a couple of pictures showing the consumed electricity v delivered energy.  Might sound a stupid question - but says in december consumed was 516 - does that mean that my whole system only used that much energy for December?  Looking at figures from my solar stats for last year:

June 417kwh / July 437 / August 437 / Sept - 416 / Oct - 410 / Nov - 500 / Dec - 1.04mwh / Jan - 860 

September minimal running of the system and from oct - only on low heat for the 60 sq metres

Also attached pictures of the manifold

Yes, you are right. And so far in Feb you have been using 10kWh per day for heat and HW. Which might be just enough in a small well-insulated house, but you are not getting great generation for that, only about 22kWh per day. For comparison, my equivalent usage for Feb is 93kWh used for 297kWh generated. I'll caveat that by saying usage is measured by a meter, the controller gives me a figure of 105. A lot of people find it inaccurate, so you might have used as little as 48kWh.

Where do the other solar stat figures you referred to come from?

that stats I'm quoting for electricity usage come from my Fusion Solar App