JohnMo

There should be no issue with an oversized unit, but if they don't understand it has to be adjusted to suit the install, and when set up currently it will not be over ventilating, they are Muppets and walk away.

I basically set the flow rates for each loop based on its length and when running the pump set at the lowest setting that could make the flow rates required. Once everything was up and running tweek the rates up or down based on room temperature, too cool increase too hot decrease flow rate.

Sorry couldn't be bothered reading it, but why either or, can't you have both. We are on a hill site, with lots of mature trees, we have a roof array with optimisers, but take a hit due to shade in the morning. The other array ground mounted to miss most shading.

Sounds good

The colder you keep the property the worse the issue. Just put a Shelly H&T (humidity and temperature sensor) in our garden room. Interesting image from today. First is temperature the second is humidity levels. As I heat the building the humidity drops, and as it cools it's starting to increase. Today has been pretty stable outside at zero degs, no wind. So it's not an outside influences.

Mine did exactly the same when I first started commissioning, eventually messed with PID, but before I did that I had to do quite a few other changes. But the PID hasn't let me run as cool as I really want, just slowed everything down a little at startup. Your mixer on the UFH reduces the system size quite a bit, because the heat pump supply is only drip feeding the mixer as required, some of the flow is recycling. So although there's lots of system flow, the only real flow all the time is the radiator/fan coils circuit. In theory/practice I should be able to supply the floor 27 deg flow temp, but couldn't get the heat pump to do that temp without doing exactly the same thing yours is doing. Just don't think there was enough system to absorb the heat quickly enough, I have set my min flow temp at 29.7 degs. When it's not too cold (4 to 10 degs) the heating is on for about 5 to 6 hours only. I then set up a quite flat WC curve, so it runs for longer as it gets colder. Even today and currently -1 (09:30) the heat pump will be off for the day at 10:00. One of the other things I encountered at lower flow temps, was the control hysterisis when I eventually got low temp flow started, it did a cycle, heat cut down and return temp from the floor would not reduce enough to give a start permission to heat pump. That was another reason I started running higher temps. The fun we have. And people wonder why their heat pump isn't optimised by the installer. They set it high and run to the hills, never to be seen again.

But a wife and/kids will try their hardest (unknowingly in most cases) to undue everything you do, or throw teddy out of cot, if you suggest a different way of doing things.

No really within reason, but longer pipes mean bigger pressure drops and eventually larger pipes. If it's a new build why even concider a gas boiler. We put in gas boiler, and now have ASHP. UFH manifold can go anywhere, you are just limiting the circuit pipes to 100m. Cylinder can go anywhere also, but close to UFH and ASHP makes for easy plumbing.

There should be a "PI regulator integral time" setting you can adjust, it affects the temperature control, and how rapid or slow it is. I had to bring mine down a fair amount. The setting from the factory was 255 and I am currently running at 60. The lower the system volume the lower the number required.

I was also curious how it did it, but has done loads now - in the colder north.

Me also, if I need something sorted I always call them

We just need a government that is REALLY committed to get these things sorted and not one pretending. They back tracked on new build insulation standards, they stopped onshore wind, stopped the homes insulation grants, give huge tax incentives to oil companies an EPC almost gives you extra points for going gas. Just makes to wonder.

Are only getting 02:30 to 07:30 on E7?

If you are filling the cavity with concrete, you obviously don't need a cavity, so why not build as a solid structure. Block on its side 215mm, plus block 100mm wide installed normally, gives you 315mm. Your build is 315mm wide also, plus all the faff of concrete fill.

In simple terms, the same principle used by a carburettor, but that case the pressure drop is used suck fuel in

Set the thermostat for 50 overnight, the gauge on the thermostat was reading 51 this morning. The heating cycle took 1 hour and 15 mins. Looking at legionella protection, a couple of images from heat geek. First is the recommended storage temperature, solid black line, when looking at store water turnover. The dotted black is with a legionella immersion cycle. 50 degs is well within our range for not needing the legionella cycle. The second image is the death cycle, at 51 degs at close to base of the cylinder a couple of hours after the heating cycle at least 90% have already died - if they were there in the first place. Another much discussed topic. But looking at worse case, thought better be on the safe side. Gauging the cylinder The additional gauges I added, were all reading slightly lower - around 5 degs. So would suspect as they are only within the insulation and just touching the cylinder wall, I am getting an under reading compared to a proper thermal pocket. Interesting the third gauge down reads slightly low, this gauge coincides (is just below) with the secondary returns port and although the pump has been off for a hour, there is still an influence on cylinder temperature. Tried the gauges in different positions and that position was always cooler, irrespective of gauge installed. So now have a cost effective contents gauge. So should help me optimise our water heating. So cylinder install complete, all pipes are insulated as far as practical, using mostly either 19mm or 25mm wall thickness insulation. Where I have a Hep2O or Tectite fitting or valve I used 35mm X 12mm insulation. No legionella cycle required Just a matter of a little optimisation of heating cycles.

So they took the other one back? What make did you get.

A full concrete pre mix lorry contains 8m3, so 6m3 is quite a bit. 20 barrow loads per m2, so around 120 barrow loads to give you some perspective.

Grohe shower mixers used by me, really need 47/48 degrees for a nice hot shower, 45 and it's getting cooler in the shower. Seem to be getting about 10 deg temperature drop via mixing.

I have just moved to E7 on a new build. Smart meter is installed, although due to where I live doesn't communicate, so it's a dumb smart meter. It has a day and night rate and I just record the readings manually. This what it looks like, a day and night rate. Not sure how you get around for your 24/7 heaters.

Concrete pump, easy to do, may cost you, but easy and quick enough. Wonderful things, we hire one, 5 times during the build.

Slight update. Cancelled the cylinder charge scheduled for this afternoon, so last charge finished at 7am this morning. Set point was 48, it took 45 mins to charge the 210L slimline cylinder from a 6kW ASHP. Wife showered this morning and general house usage, I also showered, shower temp ok, but not as hot as it was yesterday. So have upped the temperature to 50. Added some additional temperature gauges on the cylinder this evening. Prior the shower the normal temperature probe was reading 21 degs, but it's close to the bottom of the cylinder. So pretty meaningless to the content temperature and how much hot water is remaining. 4 cheap temperature probes, a 6mm to drill through the outer casing and I had a very basic level gauge. Interestingly the gauges at 21 degs read within 0.1 of each other. Not bad for £24 for 8 off including delivery. Tappings are 250, 500, 750 and 1000mm from top of the cylinder. So down to 50% of the cylinder height. Will check the temperature reading in the morning to see how accurate they are. To me it looks like the top 500mm of the cylinder is still quite usable. Next job is to tidy the gauges up and look a little prettier.

Think the ideal is something with the functionality of homely, but is just a temporary install. Wireless inside and outside temperature sensors and UV sensor on the southern side of the house. Almost the installer sets up a weather compensation curve, from design data. The homely type tool, is loaded with the same curve. It monitors over a week to a month time period and logs how the house responds and suggests delta to upper and ends of the curve. Installer removes the temporary equipment, and moves on.

It's near enough +/-10mm is neither here nor there. Be there when they install; our hood was supposed to slot in-between cabinets and top and bottom, align with the top and bottom of cabinet. Turned my back for 10 mins it was set at 750mm, because they always are. They had to buy new parts to resolve so took an additional week. Just watch them like a hawk would be my advise.

You could ju I'll seest replace it with an insulated and air sealed loft access with ladder. Screwfix and others sell them. Or could you space the ladder away from the hatch more, then glue PIR on to the hatch. The more the better.