Nickfromwales

He did, but not because of his swollen nutsack.....it was because he had his speedos on back to front.

All the above are spot on.

Bal is too expensive.

Crack on. May as well start at the start .

For high flow rates, the norm is to start off from the hot water cylinder in 28mm pipework to where perhaps the first bathroom gets teed off, then it reduces to 22mm as it gets further in, and then reduces finally to serve each outlet at the end of the run. It's not rocket science, and if he can do an S-plan or Y-plan he can do this. If they can't wire S / Y then bid them fairwell. It's nothing to do with RHI if you buy the kit cheap and DIY, foregoing the MCS price tag. You'll soon stop staring at your roof and be more focussed on your energy bill, which will only keep going up and up and up.

I'm with you on this one. Too much effort gone in to date to 'practice' here !?! That trowel is horribly square and sharp. At the VERY least you'll need to borrow a worn in trowel, or buy a ready worn-in one new. That trowel you've got is good for a bit of cement roughing and nowt else. Listen up boyo !!!! Not this time, ok. .

+1. Scrap the roof tiles and use the solar setup as your covering. ?

Maybe, but also the option to fit a couple of Rinnai tankless gas water heaters. Pro : capital cost Con : flue penetration annual inspection

Ok, so DHW is a big part of this picture. When you say 7 showers, how many occupants will there be to use them ?

Yes. The part that goes underneath shouldn't be spun, only the top part. That way you don't get the rubber washer displacing and the trap going off centre.

Yes your right. Read a screw fix forum the other day where they were doing this, but it would be massively detrimental to the boiler, plus it would instantly void any warranty. If serviced by a gas boiler then yes. As theres no potable water stored ( its a nigh on instant water heater ) there is also virtually no risk of legionella. No. You can get the smaller 22mm coil fitted and still run two good showers. I only suggest that a 28mm coil is used if theres 3 or more showers. Always 2 immersions on a tank this size, id probably say fit 1 x 3kw and 1 x 6kw so you have the 6kw for emergency back up ( failsafe ) and the 3kw for PV integration. 6kw lowest and the 3kw above it. That way if the boiler ever goes down you can dump 9kw of electricity into it and have at least some heat / hot water. Sparky will need to know about this asap to give you the correct supplies.

Nope. I'm fed up with buying Robux. Damn you Easter holiday. !!!!!!!!!! Bring back the hoop and the stick.

And we're going to let you .

Biggest gotcha is cross-threading the waste when you turn it in to tighten it. Makes you think it's tightened up snug underneath but it hasn't. Set it up dry and count the number of turns it takes to get it snug, then count them again when you seal and give the final tighten up.

Who gave him a speaking part ?

The number one F@@@ up by sooooo many 'bathroom fitters' and kept me in work for a good few years alone. The tray gets fitted, then the cubicle, and then the cubicle gets sealed up, as per the manufacturers instructions e.g. all around the outside and down to the tray, then around the outer edge of the cubicle to the tray so nowhere for the water to go other than in the tray. The tiles then get sealed to the tray all the way up to the cubicle and then there's big smiles all round and money changes hands. Then the trouble starts, from the very first shower. Water hits the shower cubicle junction with the wall profile. Water goes straight inside and runs down to the bottom. Some runs out of the gap between the tray and the bottom of the cubicle and into the tray to drain away, and the rest goes into the gap behind the wall profile between the tray and the tiles ( which didn't get sealed prior to the fitting of the wall profile ). That acts like a guttering and transports the water right around the underside of the tiles and out to the front of the tray where the tile sits on it. Acrylic tile adhesive reconstitutes with constant damp / immersion ( one of the reasons I don't use it in bathrooms ever ) so the water eventually gets behind / below the tray and from the front, all appears like new. Then the dining room ceiling caves in 3 years later .

No lol. Itll need to heat the UVC too, unless you have another boiler hidden away ? ?

If it's only a 28kw then we may end up going W-plan aka "DHW priority" where it doesn't do space heating and hot water together, so any time the hot water needs topping up the system will divert from heating to do so, by design. The 28kw gives around 25Kw to heating ( or heating / hot water in your case ) so going Y or S plan ( space heating and DHW reheat simultaneously) is a bit ambitious from 25Kw for a cylinder that big. You really should be taking the combi out and be fitting a correctly sized system boiler TBH. The hot out of the combi could just do the kitchen sink so it ( the moving hot water components etc ) stays active, with the heating output serving the rads and UVC via the W-plan arrangement. Controls can be discussed on a separate thread if you like, when a system is firmly decided upon. The uvc won't typically 'go down', the most likely failure will be the boiler or motorised valves. Are all the showers ensuite?

Yup. A better central location for the airing cupboard ( aka hot-press ) so even though the TS will have to stay topped up during the day, it can be better utilised to reduce losses, but also utilise the waste heat to keep your undercrackers toasty .

If your plumber will work to a design then great. If they won't, and are adamant about firing ~26kw or more heat directly into a manifold that can only consume about a quarter of that ( IF the house was being heated from cold, because after it's up to temp it's probably less again ) then you have to make a choice. It's your house and your paying the bill for the oil, plus your going to pay extra maintenance if the boiler can't fire for reasonably long burns eg run 'clean' and needs heavier cleaning of the baffles more frequently. You don't need to justify having a TS, and you certainly don't need a solid fuel burner to justify it being fitted either. Stick to your guns and ask your plumber for a meeting. Sit him down and explain why you've decided to fit one. If he runs for the hills then he's not much of a professional. ( When asked to fit 600x600 black and white porcelain tiles in a bedroom I didn't say "no way, they're not to my liking" because it wasn't my house. . Instead I fitted them to the best of my ability and the customer was over the moon with them. That's why we get called "professionals" isn't it ? A lot of plumbers still think an oil boiler can modulate just because it condenses You will need a hot return if your plumber will do the usual knee-jerk '28mm-22mm-15mm' series plumbing, or you'll have washed your hands in cold water and dried them before getting hot water out of the furthest away basins, especially the cloak. A TS will best suit your DHW needs IMO, as long as you set it up PROPERLY eg correctly specified controls, again not something to expect from joe public plumber. If you have a very good cold mains you'll be able to have pretty much constant, instant DHW at very high flow rates, with the ability to run at least 2 good showers at the same time. Not having PV is a bad idea IMO, and I'd at least run cables for it now, which is cheap as chips, if it's down to lack of immediate budget rather than purely deciding against.

Can any of us?

Deffo break it down into chunks if possible. Once set you can stand / kneel on the tray which makes life a LOT easier

Hi and welcome Plans please !

He's on hols mate

Ok, next up is available plant space and some plans maybe? The flow will naturally reduce with demand, but if the restrictors are selected properly you won't be stealing all of the available flow. You need to give ADEQUATE flow to each shower to guarantee results, OR you fit a second accumulator. A Zimlet 500L will set you back a bit less than £600 iirc but you can check on the PumpsUkLtd website under accessories. That'll give you dimensions too if you look under downloads on the same page. FYI, running 5 showers and still having a bit of oomph for other outlets is nigh-on commercial territory, so dont expect to do this on a shoe-string budget, it'll need some moola throwing at it. FWIW I would ditch the notion of the single electric shower and go all mixers. Instead, used the immersions ( 4 x 3kw in a 500 is possible if ordering bespoke ) as your failsafe, so you'll still have DHW even if the boiler goes down. Pointless in just having one working failsafe electric shower unless its in a communal bathroom ( if the 5 showers are all ensuite then no-one is going to want to share the only working shower with 4 others ). The sparky will have to be on board with this design too, so involve them as early on in the process as possible.