Nickfromwales

Why don't you just core drill for the flue? What's the construction ?

Is this to control wet underfloor heating, or elect I undertile heating ? The stat I linked is for wet, so no connection for the floor temperature probe.

If your going to buy a buffer, then get two pairs of tappings, one for rads and one for Ufh. You don't really need them to be separate tbh, but if you do tee them off one pair of tappings then each flow pipe will need a single-check non return valve so when one pump is running and the other isn't, the one running can't pull cool or cold water back out of the other circuit . Other than fine tuning what actually connects and exactly where, your looking good.

I think we're in the provisional 'join the dots' stage at the mo . The tappings will come on the cylinder already labelled / in the right place .

No, leave it at 15mm. The reason for the 22mm to it is to give it every chance at producing the most DHW it can. Once it's produced it it'll be at a reduced rate that won't really benefit from being upsized to 22mm IMO, plus you'll have less delay between the heater and the manifold with 15mm so less wait at the taps. Remind me again why this unit is going outside ?

Summat like this?

Camera = saved £££'s

Don't let the door hit you on the arse on the way out ? ? That will break the fermacell and cause a lot of unnecessary damage, so no. Why not get hold of an inspection camera and have a look see first ? Nowt worse than doing all that and there's a different fault. Will removing one tile allow you to repair the suspect item? I doubt it. Have a look first if possible and go from there. Have you double checked water isn't getting in there from a dodgy WC cistern or feed and tracking down a pipe ? Soil is quite hard to fit badly TBH.

I agree with your thinking, but that doesn't matter one jot as it's not open to our interpretation. It's a mains pressurised unvented water heater. Black and white case here to chose ignorance over regulations, excusing my bluntness, which will serve you ill. In Denmark you can follow the installation guide as is, but do the MI's state that it's ok to do so outside of Denmark, or does it say words to the effect of "please check this installation complies with the local / regional water regs of the country of installation" etc etc? Best to check that imo, before advising directiy against it ? Regarding PRV discharge...... If a million of these units got sold in the U.K. then that's a million tea cups of water unnecessarily dumped to drain, and in the ( EU driven ) U.K. that's not acceptable, particularly when just adding a £50 EV negates it. No sale, sorry. @JSHarris I wasn't referring to the eventuality of the PRV continuously discharging, so apologies for any bum steer there. Afaic it would be free to do so in either scenario so the matter is moot. Lets be honest, your fitting everything else anyway, as it's all bolted into the control group and built into the immersion, ( as per @PeterStarck's comment, correcting my assumption that the immersion was only single failsafe when it's actually dual ) so why not add the EV and have no discharging water ? If this is to be recognised for exactly what it is, and signed-off and registered according to our regs, then it'll need the control group and the EV, and I wouldn't install one any other way. The fact it's so easily, and reasonably cheaply negated, adds to my argument. If, however, someone says it doesn't need to comply with G3 because the BCO has called it, then fill your boots. Until then, fill out your G3 benchmark book .

I think our water regs frown on such an arrangement, certainly anywhere you are storing above a thimble full of water. The reason being is that your basically wasting clean fresh drinking water by design, and with an UVC it'll be with enough frequency and enough volume to warrant a design for the safe management and prevention of such waste. That's a provision for ( as we'd call it ) a hot return circuit ( HRC ) for the prevention of dead legs or delays in getting hot water to the furthest outlets from the cylinder. Dont connect the PRV to it as itcwont comply with G3 ( distances from D1 to tundish and tundish to D2 next invert etc. Also, don't connect the EV here as the water will be warm / hot. Connect the EV as per my earlier post, to the cold pipe AFTER the control group, teed in accordingly. Remember there can be no valves of any sort between the point that the EV is fitted and the cold connection into the UVC. The reason being that you must never be able to remove or isolate the means of expansion inadvertently or by a valve failure. I do, on larger installs with multiples of EV's, make a manifold and connectcall the EV's via locksheild gate valves for ease of isolation, testing and repressurising ( which have shrouds on the gate stem so have to be consciously opened or closed manually ) as they save the entire system being drained to carry out such maintenance, but I would not do this where there is only one. @PeterStarck Can you get a bent iron into that 1/2" brass plug and take a pipe horizontally to some internal space and fit the PRV there, and still get the case on ?

Hepworth is undeniably good, and after @JSHarris's efforts to use copper originally, I had to chomp some humble pie and agree that for long continuous runs in a house with open web joists, plastic is an excellent solution and DIY friendly to boot. Copper where everything is on show, and where you need neat or complex junctions. I will be fitting copper and soldering my joints until they stop digging copper out of the ground, or they put me in it, whichever comes first

Go for a digital timed fused spur allinone jobby. Non volatile memory so power cuts won't upset it.

?

Hell yea ?

It's an unvented water heater fitted into a uk home so it's G3 all the way I'm afraid. This doesn't allow for interpretation, you need to follow it to the letter. BCO will want in on this for your completion cert, even though they probably don't know what it is you do, and you need to make them aware of it so your compliant and it's recognised in your paper trail for insurance purposes. The ovetheat stat is one, not two means of achieving 'safety' as the regular temp control stat isn't a safety device, just a regulator The 6bar PRV is another, so the 3 / 3.5 bar PRV will be your third. To be honest you need to seek out a G3 fitter and get them on board now otherwise you may do this wrong and have to pay them to correct it. Criteria for D1&2 discharge need to be spot on, length of vertically falling pipe before / after the PRV & tundish etc and so on.

07939 996940 Trevor. Mention my username and the forum, he's waiting for your call ?. ?

This looks a bit more like a donut to me ?

What donuts do you have in Haggisland?

We need to be 100% sure that there isn't already one on it / in it, which needs terminating. @PeterStarck, best to make a quick phone call to technical to confirm / deny the above .

£2? Ill take 10 please !

Ignore him, he's just angry that I upset his ancestors in another thread. @jamiehamy 400 L 1590mm x 660mm @ £965 inc vat & p+p 500 L 1835mm x 660mm @ £995 inc vat & p+p Both supplied with :- 4x 3kw immersions. Inlet control group at 28mm. EV. Cylinder dual safety stat. T&PRV ( fitted ). Tundish. Injected foam with full metal jacket. I wonder which one you'll pick ? and no the second price isn't a typo ?

@PeterStarck The 6 bar reference is your need for a backup should the PRedV fail . Basically on any 'control group' aka 'multiblock' you have your primary PRedV and then directly after it you have your failsafe PRV set at 5-6 bar dependant on the UVC's maker plate / MI's where it'll state max operating pressure before failure eg "3 bar working / 10 bar max" etc. 6 bar is a good average so go with that. Clearly you have no space inside the unit so we're into remote mounted controls which need to be directly adjacent to the 'UVC'. Do you have any additional gubbings which were manufacturer supplied, eg to construct said control group? Also, your EV will connect to the control group

+1. You don't need a plumber, keep the faith. ? The reason the first attempt failed is that very little pipe goes into a ballofix isolation valve, so when you don't hold the valve straight and snug whilst tightening the nut, it goes skew and it's game over. Do as @JSHarris says, cut the pipe back and clean it spotlessly. Fit a normal isolation valve, then a short pipe, then a normal flexible hose. Push the ballofix onto your freshly cut and cleaned existing pipe and draw a line around the pipe with a sharpie whilst keeping your finger pressed onto it to keep it fully inserted onto the pipe. Use that line as a guide whilst tightening to make sure you don't lift off or go skew. DO NOT OVER-TIGHTEN AT THIS POINT! Make everything up, tightened snug but not murdered, and once all is in place and looking good just go back over yourself nipping up any obvious slack. Check and then check again after a half hour. Also check that water is definitely not creeping down the flexi and causing you to falsely think the leak is down below. Wrap a piece of kitchen roll around the halfway point on the flexi and squeeze it. If it's wet, the leak is from above ?

All of the cold done in 22mm. Tee off with 22mm to get cold to the TS, and then 22mm from the TS preheat to the Rinnai heater reducing to 15mm at the inlet of the Rinnai. Whats the distance between the TS and the Rinnai?

Just say they're all dangerous. When they ask why you think so, just tell them "cos I went half way through each one late last night with my chainsaw"