Dillsue

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??

If it's a cage clamp connector that you open with a screwdriver, look down the open end and you'll see the clamp opening when you push the screwdriver in. They are crimpless connectors so just cut off the existing end, strip off 10-12mm of insulation and carefully slide the bunched strands into the opening checking there's no strands sticking out. Don't twist or crimp the stranded ends as they are intended to be squashed by the clamp to maximise the contact area....majorly important with cage clamp power connectors to max out the contact area but not so important with low power connections.

The panels will need mounting on something so there'll be a cost for that something, whatever it is. If the fence is a boundary between the OP and neighbours it's likely to need to be aesthetically pleasing and I doubt the neighbours would want to look at the back of PV panels. It's a Solaredge system so it won't work without SE optimisers. Cables will likely need managing. I'd be fairly confident there'll be more costs than just the panels and a spark??

Plus mounting rails, clamps, cable, conduit, optimisers. Mounted vertically will improve winter generation but total for the year will likely be lower than roof mounted at an angle. If you're bothered about £ROI then maybe run the generation through PVGIS, but if you've got £ to blow crack on and enjoy the novelty

Are the DNOs able to gain any meaningful peak generation info from domestic scale PV info when they never ask for details of the direction and inclination of installed panels??

?? @Pocster is likely on a 60-100amp supply so the cabling will carry 16amp easily. If it can carry 16amp for 1 sunny day it can carry it every day. I believe @Pocster has had extensive dialogue with his DNO over adding batteries so everything will almost certainly be specced right

Your grid connection will already be rated to carry 16amp export. Your inverter will push that out for hours on a sunny summers day so not a problem to do that every day, if you had enough sun

If your still running solaredge then you can add more panels up to the max number of optimisers....24 if it's an SE3680H you've got. You also need to keep under the max DC input which is likely double the inverter rating. DNO is only interested in the max the inverter will produce so adding panels won't increase that. If you're getting FIT then you need to notify your FIT payer of the addition. If youre thinking of building a fence with panels, remember that lots of fences eventually blow down and pretty much all wooden fences eventually succumb with rot. Climate change ain't gonna make future storms any less intense and likely the opposite so use battleship engineering

We've got friends living in a large solid walled 1800s house and their ASHP works well for them. They've got insulated UFH, fairly recent DG and deep loft insulation. No IWI or EWI so they've not gone mad with insulation but are still happy.

There's only you that can decide on any prep mods for an ASHP. All the previous posts have started to scratch the surface on the things you need to consider before you make the decisions. The problem you have is many of those posting will have their own preference so what one person says is right for them isn't necessarily the right thing for you, or others, the size of rads being a classic example. I want the best system efficiency so have designed for a low flow temp and large radiators as I'm not bothered about large rads but dont want the cost and disruption of removing floors to install UFH. Others don't want or can't have large rads so are running with smaller rads/higher flow temps and living with higher running costs but lower installation costs. Neither option is right for everyone.

Are the 2 strings of 5 getting wired to separate MPPT inputs?

Care to share how it failed?? Intrigued to know to avoid repeating the cause, if possible

If your designing for a low flow temp then yes, just move the pipes from the rad to the UFH.

A large emitters surface area is what works best with a HP so that it can work at low temperatures. UFH gives a large area without being intrusive but radiators can give a big enough surface area too. Retro fitting UFH is more involved, intrusive and costly than radiators so it's up to you what you go for depending on your preference for the type of emitter versus your budget. If you've already got usable plumbing for radiators then that's a plus for rads. Hopefully you already know what's involved in installing wet UFH so you'll appreciate that it's pretty disruptive to install. If youve sized your rads to operate at low temperature, the plumbing involved in swapping from rads to UFH is a small proportion of the work to install UFH. The other consideration is to look at your insulation and draught proofing before you spec a new heating system.

If your boiler is now defunct, my advice would be to have a look on ebay or marketplace and get a secondhand replacement to repair or replace what you've already got. That will buy you time to answer all your questions and work out what you need/want rather than rushing into throwing an ASHP under pressure to get the heating back on.

No problem fitting a bigger expansion vessel, but if this EV is in an existing and previously working system, why do you and your plumber think its suddenly become to small??

If it's a new system then it could be an undersized expansion vessel but if it's been in service for a while the much more likely the expansion vessel has lost its pressure or the diaphragm has failed.