Nickfromwales

2x 12’s is a LOT of hot water capacity! Reason for that?

You’re good to go Bruce. ??

Also, if a bedroom is mothballed, you’d get no heat from it’s origin so the hallway would then get nowt from that loop.

They won’t sign off on that design as you’d then be dissipating heat into the hallway that’s destined for satellite rooms. That would see reduced flow temps arriving at those rooms. Best to remember that this is not a full ‘passive’ insulated raft, it’s a relatively thin screed over insulated block and beam so will be heavily reliant on the design specifications not being lost. I’ve suggested to @Russell griffiths that he insulates the flow pipes where the runs are congested and just uses the return ( residual ) heat to warm the hallway. The hallway loop should not be removed though, as it’s cost is negligible, and to not have it wouldn’t make any sense ( imho ) even if it doesn’t get used ( for provision of auxiliary heat in the hallway ) for 10 months of the year its better to have it than not to for the sake of £100.

You need to check which family of gas this is permissible to be installed onto. The advice needs to come from the actual installer, not an Internet forum ?.

It’s a “fusion weld” fitting that you want ( need ). If it was me, I’d not fit anything else, especially on higher pressure ( if LPG ? ). The last thing you want is a tank of gas gone to an undetected leak. No short cuts with gas in my world sorry.

I’ve only ever used standard compression tightened up fully and never had a problem tbh. The Euro rubber reducer deffo looks a good solution if you’re not a plumber and want to fit with more confidence.

First question, why is the timber floor necessary? If the floor was tiled and they were glazed ceramic or porcelain then they would never have breached damp upwards, and if using a DPC then it would be bombproof. Hammer in fixings with an all plastic contact surface, installed avoiding grout lines ( which would be the only weak points as far as damp bridging is concerned ) would have caused no issue whatsoever. So, why the timber floor ?

Yes, as due to the very low volume the LLH can remain inline during cooling. They come with factory insulated jackets so make sure you go for that option when buying or you may end up with a condensation bomb.

It’s the flow rate that the ASHP needs to see on the primary side eg the flow to and from the unit itself. To ensure that is always met on low energy builds I design in a low loss header for most instances, basically just a tiny buffer tank, to achieve hydraulic separation between the ASHP and the load. That allows the pump of the ASHP ( primary side ) and the UFH pump(s) on the secondary side to never ‘meet’ hydraulically, therefore the primary side is nigh on free-flowing. You then just set the primary pump to the desired flow rate, eg the rate that satisfies the minimum unit flow rate requirement, and then it doesn’t get affected by changes with downstream loops opening / closing etc. Plumbers usually follow the MI’s, so if they’re at all worried you’ll probably end up with them wanting to fit a buffer tank.

Stick to one manifold. As long as the runs are 100m or less you’ll be perfectly ok. As peter says, ask Wunda for the auto balancing actuators and you don’t need to do any commissioning whatsoever. Just plug and play, and go to the pub. Where the pipes are congested, just insulate the flows and leave the returns bare. If you’re on an ASHP then stick to 150mm centres to keep the water volume high.

As above. Fit and forget.

Also, make sure you’re cleaning out all the bits of goop and PTFE tape as they’ll go into the float valve and cause it to fail early.

Wrong fitting You need a tap connector not a female 1/2” BSP as shown. The tap connector will have the seal inside it already ( assuming Hepworth ) so nowhere to go wrong.

They’re not cheap for anything robust, so decide how much you want to part with before mentioning car port or “solar pergola”..... This is what is in the NSBRC if you want to go and see one in the flesh; https://en.irfts.com/pergosolar/ The one there is 2 panels deep ( landscape ) by 3 panels wide, measuring in at 6m x 2.5m give or take. Supply and fit for that is ~£10k including delivery and installation, so a big chunk of change! The aluminium system above is very nice tbh and includes such trinkets as a hidden rainwater runoff system, which has the down pipes in the legs, but after hearing the price most run off in the nearest opposite direction. I’d consider putting an in roof system over an oak frame setup if you want the best bang for your buck. At 4x7 you could get an on-roof setup with 16 panels ( 4x4 landscape ) but for a much nicer look you’ll need 4.5x 7.2 to allow for an in roof setup which will look a LOT nicer. 16 panels @285w pp will give you 4.5kWp gross output, so would not be insignificant, but you could go up to 330w pp and then you’d be looking at over 5.2kWp. Do a survey for shading as that will dictate what you’ll end up with from each solar day, and then start the maths as to what is sensible to invest vs the estimated break even point and RoI over the next 25 years.

Moisture resistant plasterboard is ample, if used sensibly and in conjunction with a tanking solution. Why spend stupid amounts of money on something that requires tanking ANYWAY? If you want something waterproof then cement board ( Aqua panel etc ) is a one-up option but if you’re tanking is still overkill imo. Ive a 1/4 century of high-end bathroom installs under my belt btw, so am not making these comments without care and confidence.

Chock it up, and then wind the legs up as per above. Almost every single DW I’ve ever fitted has the screw at the front to raise / lower the leg/s at the the rear. RTM ( Read the manual ) or google the fitting instructions for details. ?. Replace the wooden board with cement board / other. Why the ‘support’? Timber floor?

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.