Dillsue

When you tighten the screw into the clamp it expands the clamp so it's tight in the rail and immovable. If the screw isn't tightened up the clamps I've used slide OK. They aren't loose in the rails channel but they slide OK. Maybe you've got the screw in to the point it's starting to expand the clamp??

No idea if it's the same on your HP but on our Therma V whether you have an external thermostat or not is set with a DIP switch on the controllers PCB. If ours is set to be using an external thermostat it would need a shorting link(or closed contact from the thermostat) fitting on the thermostat terminals to give a call for heat and get the HP to run. Might be worth checking how your thermostat interface is configured to make sure you've not inadvertently selected it to run under thermostat control when there isn't one. Or just drop a link on the thermostat input. Still puzzling why your flow switch is showing OFF

Our LG Therma V from 2020 has a back up boiler feature that is documented as shutting the HP down and switching a volt free contact at a configurable outdoor temperature. I guess later versions will/may have that? I beleive some of the electricity suppliers offer tariffs where they can control your heat pump in return for a discounted rate. My brother has just moved his new Vaillant on to that type of tariff with Ovo. Whether you can get both temp and tariff switching in one HP I don't know but LG and Vaillant may be worth looking at to get your research going.

In your screen shots it says the flow switch is OFF. I don't know which way round Daikin set things up but if flow is detected I'd expect the flow switch status to be ON??? If you're using an external thermostat what are the heating minimum and maximum setpoints doing? I'm assuming those are air temperature limits rather than water flow temp??

So a 40 degree average rad temp probably needs a 43ish degree flow temp which is way more than you want to be running your UFH at. As others have said you'll need to throttle the flow through your UFH loops to run with the higher temp needed for the rads. If you're currently running your UFH below 30 you'll not be getting alot out of the rads

What flow temperature did the installer size the rads for?

I think the "grid load" is your house consumption, hence the picture of a house. Have you got a clamp on multimeter/ammeter that you can verify what's coming and going to the battery/grid/house and check your measured readings against what the app is showing??

First screen shot looks fine with 8kw from your battery plus 4kw from the grid feeding a 12kw house load. We're you using that much at 18.43? If those figures are correct then it's hard to see how the CT clamps are the wrong way round

That's likely the width of their mid clamp which could well be 24mm

My HP isn't a CE pump but has lots of connections/functions that aren't particularly well documented so its an evolving process knowing what I need/want to connect. If CE specify a certain number of cores and there's no other signals that you may want in the future then run with what they suggest. On the other hand if there's other connections/functions that you may want to use in the future then pulling in a larger number of cores is going to make life easier to hook up additional signals in the future

Double check that 7 cores is enough bearing in mind that 7 core cable is usually 6 core plus earth. You can sleeve the earth if your really stuck but not best practice. I've just installed a second 7 core cable to pick up some setback signals but should have installed a 12 core cable from the outset!

At a guess I'd say our IntaKlean filter mesh is 2-4 times the surface area of the mesh in your picture, so my view would be that your strainer is potentially too small. Have you checked if there's one fitted internally in the HP? The Vaillant hydraulic schematic I've just looked at has a mag filter in the return leg from the CH

Where's your installer? Should he be explaining how he's designed/installed things and setting the system up for you??

I'm not sure what type of filtration Vailant specify but LG specify a magnetic filter which must be installed. As well as catching anything magnetic the IntaKlean one we have has a large fine mesh strainer. If Vailant specify a mag filter then you can bin the external Y strainer in your picture and get the correct filter installed. Our HP has a Y strainer fitted inside the HP casing which is rendered redundant by the mag filter, but worth checking your Vailant doesn't have an internal strainer as you can bin the external one if its got one internally.

In this context "their son" is anyone who doesn't understand what the regulation is for and inadvertently or intentionally removes the export limit without considering the implications. That's a potential spin off from by passing the regulation which was being hinted at

My mis understanding then. Originally you said 3 x AC coupled battery inverters connected in parallel which I took to mean they were all connected to the grid.

And if the person doing that was your neighbour and their son inadvertently reset the limit to max export that subsequently pushed the grid voltage up high enough to trip your PV would you be happy? If the same excess voltage tripped another neighbours medical equipment, would they be happy? It's all regulated for good reason and I'm sure you know whether it's right or wrong

You're understanding is correct

If you connect any generator to the grid, the DNO gets involved whether you intend to export or not. It's a legal requirement covered in the National Terms of Connection that everyone with a grid connection is signed up to via your electricity supply contract. If the generator is a PV inverter with a G98 cert you tell the DNO after you've connected it. Anything else you ask for permission BEFORE you connect regardless of whether you've set it to zero export. Eon won't have approved a system for export as only the ENA/DNO can do that. Eon may have agreed to buy any exported electricity

?? You suggested 3 G98 devices in parallel with 1 as master and retain the G98 certification which isn't possible.

My comments were on parallel wired G98 devices where they are all connected direct to the grid. If you are series wiring then it's only the final device connected to the grid that needs to meet the DNO specs

With more than 1 G98 device wouldn't you have moved into G99/G100 territory with the master inverter doing the G100 management??

What would you do if you had the G98/3.68kw export limit?? If that would make a difference to your plans then throw in a secondhand G98 inverter, get the DNO to make any mods needed to accommodate that and you've upped your export limit

Solid fence is a good start and I guess a nice sparky will do whatever you ask within the bounds of decency and electrical regs

Doesn't an existing fence count as property, as opposed to a free standing ground mounted array??