Nickfromwales

To garnish the above, if you were concerned about regular interruptions of the cold water mains supply as well as regular power failure, this overheat solution could be fortified with a cold water accumulator for any serious paranoia. These ramblings will no doubt have to be in accordance with the guidelines set out by HETAS so please dont take these all as gospel without prior consultation with a suitably qualified individual. The side effect of fitting the accumulator would result in you having a top-notch water supply too.

Check out this post to see the pressure reducing valve and capillary probe operated quench valve that ran through a 12kw coil in that TS. The company Dedicated Pressure Systems have the patent ( or did have maybe ) for that concept / design. We binned it as there was no need for it, the PRedV had failed, and the dry pocket for the capillary probe was rotted through and about to dump a few 1000 litres of water into the house whilst M'lady was out at work none the wiser Could easily be implemented in a solid fuel arrangement and tbh its a far better arrangement imo, to quench rather than dump, or to have a combination of the two. IIRC the quench valve operated at 95oC, so you could easily have a dump to a second thermal store ( what id do ) or to a heat loss rad in the attic. Theres no way id ever have a heat dump radiator inside my house as it would be lethal at those temps. Heat dump rads go in attics or garages, and should be caged even if in the garage. You'd have no choice or it would be continuously dumping heat by convection when you didn't want it to. +1 on the energise to close type, aka stored energy, and its the same as fire dampers which close using the stored energy that was used to open then eg by charging a powerful spring ( hence they're always low geared motors which take an age to open ). As Peter says, if I was ever looking at this as a solution id have the 3000L TS and use that as a buffer / dump. From there you'd be able to do 24 / 48 hrs of timed space heating and have DHW, but id also fit ufh pipes into a 200-250mm thick concrete slab too as a secondary storage / buffer and to regulate heat output into the rest of the house in a far more comfortable and manageable way. UFH pipe is just too cheap to not do that, its a no brainer. With the thicker slab and the huge TS you'd be able to become far less reliant on the stove actually being lit and burning so often, and instead just relax a bit and live Other than that you may find yourselves slaves to the WBS and thats not cricket. It would be nice to go out, and still have a nice warm house to come back to with oodles of DHW available whenever you wanted it, and then just lighting the stove for a few hours of an evening when it suited you best. A Solar thermal or solar Pv system would compliment this arrangement beautifully. Sun shines on the roof and charges your heat battery ( TS and slab ) and away to go. Even a small array of either to offset losses would be a massive benefit.

It is a TS, just a plastic weird looking one. Not sure how they get around no certification? I assume that means no G3, so maybe its a manual fill gravity vessel with one or more coil for heat input and another, if required, for DHW output. Agreed, lots of patter on that website, but few facts. Apparently square ( rectangular ) TS's are a good option where space is at a premium or where internal doors have been swung and the openings are restricted. IIRC @djvasey went with a Jaspi Ultrastore 500L. Not a bad price either but only suitable ( or necessary ) if you have multiple heat sources as David did.

Interesting After I read your comment re the 4kw output, I rang WB and spoke to technical ( as I have another 2 clients considering gas ) at some length. Their response was that they do not produce an 18kw boiler in any guise that can modulate lower than 6kw, with the 4kw only available with a 12Ri boiler. They further concurred that the design of driving the boiler directly into the matched low load wasn't recommended for maximising boiler efficiency, due to the lower temp of the flow and return and lack of promotion of condensing. As I said, it will work, but in a smaller house with a lower ventilation and heat loss figure it wouldn't be the way id design it. With no hydronic break between the boiler pump and the manifold pump, which have differing potentials, you either have to have a bypass, a Low Loss Header, or a buffer tank, so I assume yours relies on a bypass ? All interesting and thought-provoking stuff The plug and play WB greenstar stuff is simple to install and maintain, but is only one of many ways to skin one of many differing cats. If I had, for eg, put a 400L UVC in a previous customers home, instead of the 400L TS I fitted, they'd have been on the phone the following week to say the hot water had been running out @oranjeboom does sound like they are ok with a more conservative DHW solution, but different horses for different courses.

Agreed, but where will 60oC water go? To mixer taps or thermostatic devices to be blended down. The TS comes with a factory fitted TMV, so only deliver ~50-55oC by design, thus offering reasonably similar sustain by means of blending at 'source'. I maintain that each solution should suit its owner, so yours suits you, but may not suit others. A TS heated ( fortified ) by PV or E10 on a cycle would be set to heat to over 75oC so they're not worlds apart by any means. Throw in the two birds one stone appeal of the TS, plus its better DHW production "on demand", and you've got a strong case to go with it imo.

Yes, because I was worried it would end up downstairs with the weight

Is the design figure not deemed as provisional only?

Hi Louise. Could I politely ask that you make a brief statement in our "introduce yourself" section to explain your posts please. Thanks. Mods.

To add, if the combi / SA option was chosen, you could go for a 12kw SA or a pair of 9kw ( so 18kw total ) and offset some of the space heating too. 6 hours of sunshine would charge that lot up and provide a LOT of storage. The gas boiler would then become a standby device for a good 60% of the year. Dont discount an all-electric heating / DHW solution too quickly, as its definitely a contender if PV + E7/10 is in the picture, and is deliciously simple, clean and nigh-on maintenance free, plus no annual servicing or gas / G3 tickets.

OK, now I've slept lol. You think this would get easier wouldn't you eh? First off, ill assume that a buffer will be integrated as you have gas and UFH and I personally would not recommend you running the UFH directly from the boiler. Maybe one day a boiler manufacturer will produce a dual burner boiler which can deliver normal service temperature flow plus very low kw at flow temps that promote full condensing. ( Dragons Den ? ). Bearing in mind that you'd have to keep a TS or an UVC hot for DHW then there is a strong argument to do away with the buffer and go for a single TS. The good news is if you put a whopper of a gas boiler in, you'll get away with a smaller TS, lower set temperature ( so lower standing losses ) and nigh on constant instant DHW at high flow rates. After a week of staring at a TS, I can say different. The way hot water comes out of an UVC is very much like the way it comes "out" of a TS. With the digital stats we had in, in various test locations during "Operation Doomsday Heating Device", its quite clear to see the heat effectively rising up into the top of the TS whilst the DHW PHE flow ( upper most side connection of the TS ) draws it into the DHW PHE for conversion into DHW. Accepting that particular TS design was ( sorry @newhome ) a steaming pile of dog shit, it still managed to fill a 2-seater bath ( well bloody swimming pool TBH ) with only a 1/3rd of the TS preheated and managed it with the ( 40% undersized ) boiler set to max input, so I was still reasonably impressed with its ability to turn boiler flow indirectly into DHW production even through an external PHE. The bath tap was running for a good half hour, and it would have EASILY provided 3 good simultaneous showers for 10-15 minutes as it was. If that TS was serviced by a 37-40kw oil or gas boiler, it would have done the 3 showers constant ( as in left running 24/7 ) im sure. FYI, the electric 3-phase boiler there was a 24kw and struggled, so if your considering good DHW production you really need to go bigger on the boiler for better performance and faster recovery / shorter burn times. Also remember that a 40kw gas system boiler will modulate down to ~9kw if ever necessary ( so don't think you'd be burning more gas unnecessarily because you won't ) . Fortify that lot with a conversion to integral DHW coil instead and you lose a pump, a PHE, a flow switch, the extra losses and dead leg delay, and its a winner for a DHW / space heating solution in one box. With the TS you'd be able to engineer the flow and return of the boiler to reside in the optimum condensing range thus guaranteeing that you get the stated boiler efficiency for the rest of its days. Having PV further fortifies the introduction of at least one type of cylinder of course, so your already going down that path anyhoo. You could ditch the DHW storage cylinders and go for a high-flow combi + small buffer, but then you'd really struggle to provide 2 simultaneous GOOD showers, and wouldn't be able to store anything produced by the PV beyond the capacity of the smaller buffer........ unless....... You have a good high flow storage combi, and you feed it with pre-heated cold water via a Sunamp. The SA would also give you the buffer medium that the ufh would want, but would add a little complexity to the design as it would need to switch from heat in ( from the boiler ) to heat out ( to the ufh ) or be very specifically designed to do both at the same time. A fail-safe would need to be installed to stop the gas boiler from ever cooking the SA, but it would make a neat two-box solution and use the PV effectively. The SA comes with a box of tricks that tells the boiler to stay off if PV has done its job too, plus you could also fit a thermic changeover valve so if the SA is hot enough, DHW flow bypasses the combi and goes directly to the taps. This plumbing lark is so simple, I'm surprised its even discussed here tbh And breathe. LPG wok burner No standing charges and tiny capital expenditure = more money to spend on Sunamps and PV

Id wish for a passive house, a big PV array, and tell the gas company to FO. Battery storage will soon fortify that, in hopefully the not-too-distant future. IMO setting fire to anything is a step in the wrong direction, as fossil fuel is only going in one direction.

Not quite The 18kw WB modulates to 6kw, the 12kw is the only one that drops to 4kw. The problem is you then step away from the condensing range and the efficiency drops off. Most boiler MI's state that you should mitigate, by design, the risk of excessive short-cycling, so if your running a passive house level of heat requirement then this would be an install that would be frowned upon by the boiler manufacturer, and may, in the worst case, cause issues with warranty claims ( if they can demonstrate that the installation is not to their stated / required standard ). @HerbJ, I dont know what your delta flow is for your UFH and what your max ventilation / fabric heat losses are, but to be in optimum condensing range you should be targeting a flow of ~600C to get the stated boiler efficiency ( that any design should deliver ). I accept that some folk are happy to compromise and do away with the cost / complexity / lost plant space of the buffer arrangement and will finish by saying that it will work, just its not ideal. In your instance, if I was designing it from scratch, id have insisted on the buffer with that set to sit at 50-55oC target temp, and id have put a separate pumped circuit to the towel rads from there so the towel rads could run hotter.

Solder it and do as per my pic . If it leaks, I'll eat my hat, his hat AND your hat. Crack on boyo .

@@@@ the solar thermal. I could sleep on an electric fence.

About right, if your using 12mm tile trims . 100% what I would do, and I posted pics of the last one I did where I did exactly that. Bombproof. You can get one of those backplates that's end feed too, not compression, so bombbombproof. That is an actual word btw.

None on the edges, the stone resin is tougher than you are heavy . Back filling the gap along the front leading edge with tile adhesive is what I do, but I doubt I'd it makes a blind bit of difference TBH

Good to hear your not bitter

Don't. .

A roll and a half .

The area that's been ground flat is where you need to apply the adhesive. Don't fill the rest of the area, and don't put any where the trap will sit. In the dip either side of where the trap goes put a generous blob and let it squeeze out as you push the tray into place.

And I'm there in an instant. People may frown, they're T-total vegetarians most prob

I know little or nowt. Mostly nowt, occasionally a bit. Sometimes the bit is relevant to nowt and has little use. Apart from that, I'm your go to guy.

I know little or nowt. Mostly nowt, occasionally a bit. Sometimes the bit is relevant to nowt and has little use. Apart from that, I'm your man.

I can be there Monday, £110. ?