Nickfromwales

https://www.cylinders2go.co.uk/shop/stainless-steel-unvented-cylinders/unvented-horizontal-cylinders/telford-tempest-125-litre-horizontal-direct-unvented-cylinder-2/

“Bugger”. Bath?

Can’t you fit a 15/20/30l water heater under the kitchen sink, and do an electric shower? Is there a bath to fill?

Is there 3 phase available there? The 27kw Stiebel Eltron instant water heater is just absolutely amazing. Its water production is that of a good combi boiler, I was super-impressed by this. If you can convert the supply and fit cost of the Sunamp / Thermino (prob north of £8k installed with electrics and plumbing, including the new D1/2 PRV discharge waste requirements etc) and buy one of those instead, for IIRC sub £600, then use the change to get a 3ph feed to it, that would serve you well, and it’s the size of a larger, taller shoebox!. https://www.heatershop.co.uk/stiebel-eltron-dhb-e-27-203865-set-three-phase-touch-instantaneous-water-heater-3i-technology?gad_source=1&gbraid=0AAAAAD_r406R6I3CsDg1Re8V-Esxh4jxz&gclid=Cj0KCQiA4rK8BhD7ARIsAFe5LXIpAgmiAiYnFIbawprfNVfL4unFAqqJbdCD4n9dl7E5-UGEgCIJ2KoaAv4wEALw_wcB

It’s down to opinion unless the BCO is called to site as a complaint? It doesn’t have to look pretty to be functional, in a nutshell. Damp course being bridged = not your concern…perps missing or poorly executed = not your concern… If it falls over and squashes you, then it becomes your concern. You claim on their insurance, after the event. Once the fence goes back up, do you actually care about this? I can’t see why you would, but if it’s an eye-sore then just add a trellis header to the fence and worry about things more important to you? Please don’t read that as me being sarcastic, I am not, just perhaps a reality check and taking you off the boil to reevaluate

Then the fail rates change and it becomes a “lead & lag” arrangement, meaning one heater is doing the brunt of the work always. Not how I design these things. I design this so that the 2x Willis are “the heater”, with a 22mm flow in, and a 22mm flow out, and end of. I’d have to ask why anyone would want to complicate such a solid, simple, reliable setup which already promotes huge longevity? Especially when it’s in, fitted, commissioned, working, and not defective at all?

Yup. We’re just wasting time discussing a problem that doesn’t exist, unfortunately.

@Onoff the reason for fitting these in parallel is explained to the T in your link, thanks. For the benefit of other forum members: When I fit Willis heaters in parallel I make sure the pipework to each unit, in and out, is hydraulically equal (same pipework distance and size). This does indeed maintain equal flow through both units, and the notion of any problem created by “mixing” within ‘the heater’ is a dreamt up issue at best. You don’t see domestic clients pull apart a new W-Bosch combi and start adding valves to their plate heat exchanger internals, saying “some pathways are slightly hydraulically different”, do you? Fact is, cold water goes in, and hot water (the product of the various mixing characteristics of the PHE internals) comes out the other end……🤔 Literally couldn’t be easier….. The input temp vs output temp is what you reference; simply getting the sum in / out values and indeed then allowing the heaters to do the work as they were designed to do so. If however the design is hydraulically imbalanced, then flow would go through one heater more than the other, which is why I don’t do that. A lot of micro-managing type folk have discussed this with me, in other instances, unfortunately LONG AFTER THE DESIGN AND INSTALLATION HAS TAKEN PLACE AND THEY’VE HAD EVERY OPPORTUNITY TO ASK QUESTIONS UP TO THE POINT OF COMMISSIONING, often to criticise or question (more so when another plumber has been approached in the interim for a random uneducated opinion on this AND HAS GOT IT WRONG). More annoyingly, in another instance, a complaining client I installed such a system for had posted on a public forum to say the system that I installed was working “too well” if anything, but then went on (when bored and over-thinking everything as usual) start attempting to pick faults that didn't actually exist, complain about hypothetical problems, ahead of them ever occurring / or having had actually occurred, but this is almost always simply the unexplainable and irrational nature of some people. Hydraulically, a pumped system, such as the OP’s (may possibly(?) be) will be primarily piped in 22mm copper, and the Willis heaters are 15mm in/out, therefore these would then be a choke point; if, by design, the system installer had to account for the system to be able to cope with any adversities (and be reliable) then adding 2x in parallel would give 30mm of hydraulic pathway visible to the 22mm pump body therefore allowing it to enjoy minimal resistance and live a long happy life. I assume any “pro” plumber, perhaps not the original installer, if the aforementioned alterations were not bodged by the homeowner, would have made this observation before hacking into a perfectly working already installed system, and there would now be a PBV teed into the flow out of the pump and back to return to cope with the change in hydraulic difference, so as to not labour the pump. Not heard any mention of that, just isolating valves, so this is probably now to the detriment of the originally design-in longevity and reliability. Cool. Only joking, completely uncool. Irony is, that would then constitute a mixing effect, but if that design came from a “pro” plumber….then that would be ‘all fine and dandy, I expect. Just grabbing at straws here btw, so please don’t take any of this as factual, and please don’t quote (re-quote) me here as I have no clue as to what I’m doing, (via my inconsequential 30+ years experience of plumbing / heating et-al), just pure guesswork which you should all ignore I once was asked, in another instance, about doing this, and I went on to explain in detail why putting 2 in series was (IMO) a terrible idea, and that person agreed and I carried on about my business. System still works perfectly well to this day without complain or defect (Passivhaus type dwelling with an insulated raft / airtight / MVHR etc etc). As per the internal PHE of a brand new combi, in another similar instance, I suggested that the client leave it the fcuk alone and enjoy the heated water that comes out of it reliably, and as per its intentional design, as it’s worked for everyone else that has one like that….. “If it ain’t broke, then don’t fix it”. I disagree. When I plumb in Willis heaters like this, I have 22x22x15mm compression Tees where the 15mm spurs face forward. The Willis heaters compression fittings push back onto these spurs and job done. In the event of failure the 2x 15mm compression nuts get loosened off the T, the new Willis adopts the 2x reusable spurs and the lot then gets remade back as original (no cutting of pipe etc, just 2 or 4 new 15mm olives needed at most). 30 mins drain down / swap / back to work is my design methodology. When I design whole of house M&E systems for self build clientele I always factor in this discipline, eg I plumb it to make downstream service / inspection / replacement of components that we all know will eventually fail, easy to do and 99 times out of 100 without anything other than a towel and a spanner, just as any “pro” installer should.

Indeed, but he’s a grown man so just let him carry on about his business please, I’m sure it’ll be fine.

My go-to ASHP guys used these (2 different companies / installers) and on both jobs there has not been a 100% success rate, but to be fair this can be said of any soldered joint or compression joint; the big difference is when the bastard requires a huge effort and chopping out of a lot of the local pipe etc to change it which winds me up. Even a failed soldered joint can be successfully re-sweated in situ in most instances, and compressions can be removed, olive changed, sorted fast and that happens without touching anything more than a spanner. Not an issue for me as the companies both returned swiftly and made good where it was critical to do so, at their cost, but if it is a compression joint then it just needs a pinch up. Press-fit is used everywhere these days, because of its speed of installation and its relative simplicity, but nothings going to be documented here that is 100% guaranteed leak / bomb-proof as mostly it's either a manufacture defect or installer error that produces a failed joint, and that's never going away regardless of the system or product types; just called "life". The reason I stick to compression / brass / copper in all plant installations is that it has never really let me down, but I am very attentive in my workmanship (for good reason) as I would have to travel a considerable distance to facilitate a service call for such a failure which would sap a lot of the profit made from the job.....hence I try and fill & test when I am at the hotel and make sure I am back again the next day doing X/Y/Z meaning I am able to observe the plumbing to check for leaks before packing up and heading home. It doesn't always work, such is life, so one weeping fitting is not the end of the world in actuality, and you could have called the chaps back on warranty to do the repair for free? Was probably your nature to take the path of simplicity and speed, eg do the bloody thing yourself as it's quicker and easier, and you have the skills.

Why wasn't the fence taken down and permission given for access, eg so they had a fighting chance of doing at least a better job than that?

Ah, so I’ve been starved of this critical and vital information until now, yes? lol It’s ok, I forgive you. As with everything the devil is in the detail, so please give us the entire picture so we can advise correctly and swiftly, kind sir.

Lol. If it ain't dry by now it's never going to be

I'll drop the wife's hair straighteners in that, poke 3 holes in the top, and name it "Sanump". Dragons Den here I come.

Nope, it's the insulation panels which are vacuum sealed jobbies, as in the best bang for the thinnest footprint. 👍

I’ll chop it up and give it to the crackheads down the train station. 👍.

Met a chap at a public show who’d just paid £14k for 2x Thermino 210 units (replacement names for the old 9’s) and I almost keeled over. WTF.

I’d want to hear from a governing body and then have a method statement in place if doing something ‘bespoke’ and pushing these boundaries, given this is for a 3rd party public venue. I’d prob say go for B20’s not C20’s as there should be no need for the C capability.

Bean-counters prob won’t like the materials or manufacturing costs of that solution methinks, but for north of £6k for supply and fit, there’s should be enough frigging meat on their bones…

How do salt and certain metals ‘get along’? Hex is copper.

This is what I saw / heard back in the earlier days, so maybe watching these getting cobbled together then bears no relevance now, for completeness. Perhaps filling via that hole then inserting the ‘vent’ is the way now, as you say it would make much more sense. Not sure how that downstream high pressure could be held back by such a retro-fit fitting, but I’m unsure of whether the residual gap at the top was intentional / functional and allowed expansion within the cell, which it may not have if it was fully filled perhaps?

@Gibdog The extra penetration for sewage and grey water vs one duct for both will depend on whether you have a sewerage treatment plant or not If you're on a network sewer then no need to segregate them. You shouldn't really have any 'sensitive' or low voltage services in with mains cables tbh, I'm sure it's been done under duress a thousand times though, but this is a new build / new design so best to do things right. GTC (I worked with them in Gravenhill in oxford) would point blank refuse you a connection if you asked them to pull the same 2 cables into the one duct, so beware of getting refusals to connect / adopt your chosen methodology with groundworks from 3rd party providers! BT will want you to use a specific (BT56) rigid duct which they usually supply you FOC. If you search on here there are threads showing the recommended separation of incoming underground services when sharing the same trench etc which will help with economising on the number of trenches etc. Remember there are different size ducts, so some will be small 50mm ones, medium are ~75mm and bigger ones are 100-110mm (or larger), so don't install a bigger duct than needed for say the incoming internet provider (50mm is ample there). Cold mains will need the bigger size because of the minimum bending radius of 32mm MDPE, same for the incoming mains steel wire armoured cable, and so on. If you don't need a sprinkler / automatic fire suppression, then the outside taps should all come off the incoming cold mains MDPE (blue alkathene) pipe and (ideally) not after the domestic stopcock in the house, thus saving another penetration. The house water pressure can be more adversely affected by the outside taps coming after the internal house stopcock, and I avoid this whenever I can by simply T'ing off the incoming 32mm pipe with feeds to various outside tap locations, underground.

🤞

Ah, OK, thanks for the extra info. I think, to make a decent difference long-term to that one particular space, you'd need to look at it as a cube and make that shape good; floors up and ceilings down etc. The issue you'll have is that the space will constantly try and attain the ambient humidity and temperature of the rest of the build fabric. It is quite difficult to create single thermal & air-tight aka 'climate controlled' spaces like this within a functioning domestic dwelling, even more so if the extractor fan is constantly pulling humid air from floors / joist voids / rest of the house right through that room and out to atmosphere. If you're suggesting applying an insulated PB to that one wall and expect a significant (noticeable) result, then I think you'll be disappointed tbh.

A weak point for sure, and one has to wonder how the integrity and shape of the hot base section, then bloated and misshapen vs the cold lid, when brought together, are aligned for correct / sufficient purchase to be practically achieved during their 'welding' together. Lets remember that a proper fusion weld of 2 'plastic' gas mains is acceptable for large underground gas mains (high and low pressure) and these are extremely robust and almost impossible to break apart. My guess is that their process doesn't allow for the weld to be as good, given that (I assume) there is only access allowed from the outside of the pre-filled cell. Perhaps there is a lack of deep penetration so the full thickness of the cell isn't all part of the finished welded join. Who knows...I mean I have genuinely tried to think of how this could be done differently, today, but I am drawing a blank. Production-line solutions would probably be the answer, if this is now being outsourced for eg to a manufacturing giant.