Nickfromwales

Beware fitting a bigger device, if your existing supply and pipe work won’t effect the desired results

Depends on whether it’s all being squeezed down one 15mm pipe which is T’eed off repeatedly, or through well thought out and dedicated radial supplies. The difference that can make to the same cold mains is significant. Most combis have 15mm inlet & outlet whereas an UVC / TS have 22mm so can convey much more water / have lower paths of resistance. Designing a new system from scratch makes this possible, but solving a retro fit is a bloody nightmare as you’re constrained by the existing pipe work etc.

Another option could be a floor standing high flow combi , ( Worcester Bosch do a tidy one iirc, used in a lot of B&B’s / small guest houses ), and a 2-300L cold mains accumulator to fortify cold mains delivery, but you’d still need a small / medium buffer to compliment the gas vs UFH situation to get your condensing range reliable. The issue is the length of hot water draw off duration stated in the OP. No accumulator will defeat that problem, unless you’ve a room full of them.

Crossed with Peter.

Yes. As long as it’s a dedicated ‘high flow’ unit it’ll do the job. Most you can expect in reality is two “ok” showers simultaneously, or one excellent shower, but two is possible. This is remembering that an instant hot water heater, of whatever fuel origin, is ‘cold mains dependant’, so if during the two ok showers someone flushed the loo, you’re going to know all about it. Same if any white appliances are set to run whilst you’re showering that would be a disaster. Discipline is number one in this scenario, so with unsympathetic teenagers in the mix I’d forget anything instantaneous here @MrsDeS. Boiler + thermal store is what I’d fit here, or a bigger than necessary UVC ( unvented ( mains pressurised )) cylinder, but you’ll then suffer the longer term ownership issues when said water thieves fly the nest and it’s just you guys there. As you have UFH ( and why have you oversized the rads if you’re on gas not a heat pump ?!? ) I’d say fit the TS ( thermal store ) as it’ll give you a buffer for running the UFH and give you your condensing range, ( which you won’t get at very low temps btw ). Downside is you need to keep the TS hot all summer for DHW ( same as you would with an UVC, but typically hotter than ) so losses need to be considered and managed. Best way is to put it in the airing cupboard to warm your trollies all year round. Cold mains needs to be surveyed before deciding, as you can’t get a pint out of a half pint pot, and you’ll probably need to have all the cold mains in 22mm and pipe accordingly for your needs.

?. I have a POE switch and am about to hook up a single AP for my kids to be able to use their iPads outside. Did you just link the AP’s direct to your POE switch and off to go? With a single AP I assumed that would work, but with multiple AP’s I couldn’t get anything working without the key ?

Sounds like the turn screw adjuster on the fill ( float ) valve is set too high and water is getting to the top of the overflow pipe and then discharging to the WC pan. Can you remove the flush plate, and then observe if the water is indeed getting to the top of the internal overflow ? That pipe should be dead centre of the cistern when you look inside. If it’s not getting to that height and the unit is brand new, it’s likely the cistern flush valve insert isn’t seated properly. Check Grohe / YouTube for service info and follow that. They’re quite informative. I fit Geberit routinely so am a not completely familiar with Grohe stuff, sorry.

Why don’t you buy one and use it to survey the house? You may find one in the middle of the L is sufficient. Or that two may just become advantageous. I’m fitting Ubiquity AP’s for my current clients after great success on previous installs. The paperwork suggests needing the safety gateway / router doo-dah, but you only need the ‘key’, as if you’re connecting to a BB suppliers own hub it will fight with the Ubiquity gateway. Good to remember, also, that it’s the device that jumps to the best signal, vs the AP’s ‘grabbing’ the device when it gets ‘near’. Devices will look for the strongest signal and will jump from A.P. to AP by themselves.

Check that it's 15mm not 16mm ( as most MLC pipe comes as as standard ) or you'll have to keep converting back to 15mm everywhere

Do you have a pic of the junction between the floor and the tray edge?

Not sure TBH as I've never disassembled one, just cannot think of what else that could be..... Possibly a stray blanking plug installed by a manufacturer of one or other bits of kit upstream? My best guesses I'm afraid!

FWIW, I would not fit a factory finished tray flush with the floor. You should, ideally, go for about 15mm of tray being proud of the FFL so you have some 'meat' there to seal back against for water-proofing immediately outside the tray ( aka the splash area ).

Looks like one of the shields around the moving part of the ball valve to me. Can you strip that out and rule it out?

You have to tile it then

https://www.ebay.co.uk/itm/15mm-27mm-PIPE-INSULATION-10m-thermal-lagging-protection-hot-cold/401593150594?var=671333738851&hash=item5d80d12c82:g:luoAAOSwBFVbjjgR Just slides over the pipe, but a 2 man job for long runs. Glass-fibre rods ( electricians ones ) will make short work of threading them through.

Were you planning on having the tray finish flush to the final floor covering? If not, does the 5mm present any other issues? That's a nice looking tray, not seen those before, so I'd go for that unless 5mm will cause issue elsewhere? Any photos available of the actual waste / underside of the tray?

https://www.screwfix.com/p/ph2-drywall-screwdriver-bits-ph2-2-pack/6623v

Q1, yes, just a simple 32mm compression fitting. Do NOT lube up the compression side that goes onto the chrome tail. That needs to be dry fit to get the rubber to ‘grab’ the chrome surface. Q2, dunno. ? Suck it and see, but the trap should just screw straight on.

They’re definitely notable on the higher setting, so deffo go for the 2-speed. These also come with a remote control ( hard wired usually ) to save your back . Remember to factor in maintenance as the heat exchanger needs periodic vacuum / brush cleaning ( or possibly blowing through in situ with compressed air ) to stay efficient. As these suck air in down st floor level they are prone to dust / hair contamination which will eventually render them ineffective.

Just buy a regular socket and one with just 2 or 4 locations tabs ( bump stops ) and ping them off with a small cold chisel. Instant slip coupler and no trip to the merchant if you already have one to hand ?

I always go to 28mm if there’s anywhere near that many bends. In honesty I can only recall a couple, where they were 22mm for a couple of metres and straight out, where I didn’t upsize.

On an UVC always, but, you can get away without one on primary circuits as it’s just the volume of expansion to get rid of. BCO’s never chase on that but are all over D1 & D2 on potable as it’s drinking quality water being ‘lost’. There are several waterless traps ( sealed ) which are transparent, so you can use one of those if a visible discharge is required internally. Where it runs to an outside wall you can rely on that as means of visible discharge.

You don’t really need the tundish as it’s not potable. Change it to a waterless trap if you’re getting draughts coming up

I’ve never seen a shower trap that isn’t top access ?. The grille on the top usually needs a tool, like a crotchet hook, to remove that part but they have bucket sieves inside in most cases where that catches the worst of the hair / other. FWIW, some don’t appear to be serviceable, but are.

Firstly, why would you consider a deep tray? They’re not exactly ‘beautiful’..... The litres per minute discharge rate is what usually dictates the size of the waste. A slimline tray is deemed more likely to need efficient means of discharge, hence the larger diameter, but the deeper trays can use a bit more gravity to get rid of water. Suds are the nightmare so cause most issues, but make sure the traps regularly cleared out and you should be fine. To be honest, if the waste pipe work is in 50mm instead of 40mm ( 2” instead of 1.5” ) then that will pay huge dividends. 50mm gives a decent air break ( air can travel back up the pipe over the discharged water travelling down it giving relief from any vacuum happening ) and is something I practice without exception. Taking the chrome cap off the shower waste will also show how badly the suds stop natural discharge.