Nickfromwales

Would need to be holy water for you ya heathen 🤣.

Water?

Installed prices are quite significant either way tbh, so if paying for the whole shabang you may as well have the best item installed if the install costs are roughly the same anyhoo. I’ve fitted Panasonic and am very happy with them, also.

https://www.elementshop.co.uk/prowarm-aluminium-spreader-plate-390mm-x-1000mm-with-150mm-centres-bulk-buy-1-to-9?gclid=EAIaIQobChMI987eh4W8-AIVFIBQBh0pnw6NEAQYASABEgL-MfD_BwE

A layer of PIR directly under spreader plates ( set out meticulously so as to make the plates very slightly distended eg for excellent surface to surface contact with the P5 ) will add to the mineral wool and pay huge dividends. The wood fibre could be used instead, but if it were my house I’d use PIR for the uplift in the performance credentials. Yes, already noted, Sherlock 🤪. Just saying the underside of the heated pug tray would be only protected by the wool and also subject to ventilation heat loss from the free air movement in those underfloor voids. Thus, the PIR, sealed and made draught-proof, would ( should ) be a minimum spec under the pug tray. Prob struggle to get 25mm under unless the tray bottom was 11mm ply and in-filled with PIR before loading with the pug mix. Wool > PIR > spreader plates c/w 3x16mm pipes per tray / void > 22mm P5 > 6mm ply > floor covering = 👌

I'm not a fan tbh, as the vulnerable external mitres take a bash from hoovers etc and start to fray. Pine is much more robust imho, just a total PITA for prep / prime / paint. Get set up ( either way ) to spray all of these BEFORE installation, as this removes a ton of downstream backache and cutting in.

The're about to install one via me for my current full M&E package clients. Defo Rolls Royce, Bugatti even, but very good credentials for when it needs to count and boasts a CoP of 6 if installed to their ( very fussy ) criterium. CVCsystems also design and specify for my MVHR stuff, and Nick Vaisey is their in-house passive guru who is extremely helpful. Vitor is the ASHP guy, and he has also been very helpful in coordinating the above SE ASHP installation. Thoroughly recommend you talking to these guys.

That pipe will last longer than us mate

Yup. The caveat is that using up the depth of the floor joist means a diminishing space for a high-performance ( or indeed any other ) insulation under the pug screed. Needs a bit more thought Why not fill the depth of the joist space with the best possible insulation, atop the wool product, as a secondary higher ( highest ) performing insulation layer and THEN you can go for a 22mm P5 deck board minus the troughs. 6mm ply on that and you're sorted.

You will still need to insulate if this is less than 300mm from the perimeter of the foundations. Rockwool plus 25mm wall pipe lagging will suffice. Exp foam is fine with MDPE btw Just spray a little water into the 110mm pipe before applying to help it cure / expand.

The mention of "Landlord" suggests a rental? If so, raise these concerns with the property owner and allow the installer and the person who paid for the work to be do ne to discuss this between themselves would be the 'correct' path here. As far as the reasons for boarding, if this is a high / multiple occupancy building / flats over flats etc, then the boarding would ( could ) be a fire / smoke barrier and therefore it's installation would ( should then ) have been overseen / inspected by a BCO for correct execution and integrity. As for nails left sticking out to the point they are damaging the LVT flooring, that is just shite workmanship. If you're renting this is not really a matter for forum-folk, more for you to take up independently with the person you pay the rent to.

Not relevant, as this is heating which has always used circulation pumps. Gravity has been for feed and expansion only.

I very rarely test a domestic system like that. District often has 100’s of m’s of pipe in a linear run so it’s part of the installation guidelines. For domestic a blast with the cold mains ( typically around 2-4bar average ) will be more than suffice. Domestic never sees north of 5bar tbh.

Why test at 10bar? 1-3 is average, over 5-6 you’ll need a PRedV to drop it to 4. Just hook up to the cold mains and use that?

Don't worry, we'll learn you good, Jethro

Have you allowed for the restriction of the outlet that each pipe terminated into? VS what will come out of the end of the pipe? All completely academic imho, as larger pipes / higher dynamic flow rates etc are all arrested by the outlet and its governed output rate as set by the European standards for the max typical flow rates ( in line with water consumption regs ). The gross variables involved make this nigh-on incalculable afaic. The flow rates will all shift the second another outlet is opened elsewhere too, so further reducing the dynamic flow rates. For actual real world experiences, I have done multiple 10mm and 15mm radial whole of house installations, with pipe runs up to and beyond 30m, and there are no real world issues at all. Either install a HRC or just wait. As for filling a basin, you simply start shaving BEFORE the basin is full Simples!! Too much maths here, and I genuinely fear you're worry over nothing.

Don't panic about the fittings as Hep2o stuff is simply bombproof. Defo avoid doing that

MVHR + FCU's. Scrap the idea of the 40mm pipe to outside, that's mental. Route as you say to the cloakroom waste and run it all in 21.5mm condensate pipe as there will be only a thimble full of water going down the pipe at worst. You can mount the pipe off the true vertical rise eg so any drip where the pipe goes from 1st floor horizontal to the vertical drop cannot give you a drip-drip noise, simply by installing it 2 pipe widths off vertical so the water droplets ( even though.......... ........is typically correct ) cannot fall the full length of the pipe, as you certainly would hear a drip of water falling 1 storey and hitting the pipe again where it returned to horizontal at the cloakroom.

Was that to spray over the entire interior?

They won’t negate a mechanical fix such as a screw.

A simple resolve would be to get a cosmetic repair company ( such as Mr.Magic ) to fill and paint the screw holes. Agree a discount to the value of the repair. That will be the end of your problem re cosmetics* “Technically” they’ve done nothing “wrong“, just the fact that the screws weren’t put in on exactly recurring and matching centres is, absolutely, sloppy workmanship. *Closing the gaps for the AT test will be a challenge, but you can use clear CT1 and fill most voids that way. Use baby wipes to clean away excess, but use your finger with a wipe over it to force the excess into the joint vs just wiping it away. CT1 cleans off completely, so don’t worry about getting a bit of it on the face of the frames. Have some CT1 MultiSolve spray to hand for final spit ‘n polish. The installers should carry this out eg before you accept the job as complete, however I would do this myself for assurances that it had been done properly. For others who are due to receive their delivery and have an installation carried out; I am to soon take ( supervise ) delivery of a 5m long 3-panel slider on behalf of a client. After seeing the efforts ( lol ) of the first set of fitters the client and I decided the sliders needed premier installers, so I contacted Dovista ( who own Velfac and Rational ) and they gave me details of a very helpful and competent installation company to come and install. ( PM me for details if anyone wants them ). Regardless of their pedigree, I will be asking for a 30 minute meeting with the installers regarding their intended installation methods, down to every screw / fixing / finish / AT measures / weather resistance & final sealing etc. So, BEFORE they even take their tools out of the van, I will have asked for, and be familiar with, their intended methods / practices. I will be stating that screw holes, if so required, are indeed at recurring / matching / symmetrical intervals and will accept nothing less. Ask questions people, it’s your money and 100% your prerogative to do so. Expecting things to “go well” with such a significant program ( and cost ) is a little ambitious imho. Lack of a PM/PC is the usual culprit, or self builders who are running their own project with no understanding of each trade / associated disciplines. It seems it is more common for this to go wrong vs right. So you identified this and mitigated(?), which is exactly what should happen. Ask questions before, not after!!

The frames have a purpose installed metal rail where the pan tightens back to the wall covering. The idea being all of the compression happens there. The cement board should be against that if the studs have been installed correctly, and there should be, ideally, a small bead of Sikaflex adhesive bonding the cement board to the frame to marry the two together. 12mm cement board is bloody solid stuff, but that is a problem as much as an attribute, as it will hold off from the frame until you tile and fit the pan, and then, due to the high point pressure applied, the tiles will either crack on the day or a few weeks down the line. There should be zero movement, certainly none that a person could detect by physically pressing / pushing the board. Take it off, put a straight edge across the horizontal frame members and the studs at each side and locate the issue before moving on from here. You can install the pan bolts after the bonding has been done and the CB refitted, and use the nuts and washers to put this under compression whilst the adhesive goes off ( 24hrs ). If it moves after that, put the house up for sale.

Yes, about 10oC higher would prob be ok. Just enough to start running the system and then you can check how the ASHP behaves, duration of heating on / off cycling etc, to decide if it needs tweaking. Most modern sealed cylinders have a fixed stat ‘pocket’, or two, so the location will be defined. Unless you buy an open vented cylinder with foam insulation, which would be quite poor in efficiency vs a sealed and pressurised system. A dumb buffer will not have a T&PRV so go for one of those. If you require cylinders, ( UVC and buffer ), give Trevor ( Cylinders2go.co.Uk ) a shout and mention my username and the forum and he will look after you.

If go with a slightly bigger ( 80-100L ) buffer tank, and a single stat. That’ll be simple and effective. The waste heat will be advantageous, so not a worry. Possibly install this in the airing cupboard?

https://www.sunamp.com/wp-content/uploads/2020/09/D0001-1.2-UniQ-eHW-Heat-Batteries-Installation-and-User-Manual.pdf Page 26 and 32. I found this whilst waiting for my coffee. Took around 45 seconds. Was very laborious and difficult, and involved typing 3 whole words on my phone keypad……..