Nickfromwales

https://www.dkb-elegance.co.uk/details.asp?ProductID=9115 This goes together like lego, and you just screed to the top of the former. Easy enough DIY job to get a whopper of a wetroom and you can shape that to suit by cutting the sections. It's either spend the money on labour, or on the product. You're spending money either way, but why not go huge on the shower area and do away with majority of the glass? That'll save more ££. Just fit a 400mm panel on the far right, and square the pointless acute recess off by 3-400mm and cut a tall narrow niche into it with a glass shelf half way for lotions and potions etc with the shower head as far into that corner as possible to manage spray.

Well......they undo themselves...... Almost every instance I see of JG being used nobody has used the clips to stop the fitting from undoing itself. If the clip is used then I assume all is well. Just another component to buy, fit etc and without it the system is infinitely more likely to fail vs Hep2o. Every job I go to that's got JG stuff there, more so with the 15mm than the 22m for whatever reason, I see fittings which have either not been tightened from the get-go, or ones that have moved with heat / cool cycles and are all but completely undone. I genuinely do cringe when I see this and wonder ho much longer they would stay like that before popping off. The do all seem to get to a oint where they stop undoing and just stay there, but Hep just doesn't suffer from these issues at all. Cut pipe, fit insert, push it in and you're done. That's it. They even have a clever knurle on the face of the insert so you can twist the pipe and feel it 'bumping' against the seat of the fitting, letting you know you have pushed it 100% home. Hep for me, and nobody will ever persuade me otherwise. If anyone is in doubt, buy a small selection of both and decide for yourself.

I demand a re-match !!

There is that gem also. With JG.

Yup. The valve is actuated by the TRV style head and that gets its reference via a capillary wire that is connected to a thermo-probe ( which is inserted into a pocket to detect the flow temp after the pump, eg after return water has been blended back in already ) and the TRV head will only open if the flow temp is less than the setting on the TRV head. The valve is normally fully open, so it promotes great full flow rates when the UFH starts up and asks for heat, and only starts to close as the temp set at the probe meets the temp set on the head. There is no 'cold' to speak of, just the available return water and whatever temp that is.

There are 2 options available; 20-60oC or 30-50oC @Russell griffiths You need the 20-60oC @PeterW These drop down very low and are super-reliable too. A standard thermo-mechanical(?) TMV struggles at 30oC and starts whining and strangling the flow the second it runs out of cold return water to use for blending. I've been fitting these Ivar's on just about every project so can vouch for them doing what they say on the tin, and reliably, particularly on low-energy & 'passive' builds. Pump UK Mixing Kit £243.36 inc VAT Ivar Uni-Mix Underfloor Heating Pump Mixing Kit This is a well engineered Manifold Pump Mixing Unit manufactured in Italy, offering excellent flow rates, with an adjustable water temperature range from 20° C to 60° C making this perfect answer when commission the underfloor heating system for the first time and need to build up the heat very slowly and avoid cracking on a screed floors.

Lol, ok, yes you need a tool to compress the grip ring if you wish to demount a Hep fitting. So; Funny that nobody mentions that when you enjoy the tool-less extraction of JG pipe from a JG fitting, the poxy inserts stay stuck in the fittings and then you have to disassemble and reassemble to go fetch it. 30 - 15......new balls please!

Did you fit the little horse clips after tightening the fittings? IIRC you used the blue / red combos. Funny that folk all mention JG stuff but NEVER mention the clips that stop the crap design from undoing and flooding your house...... These wee beasties Forget these at your peril. PS I only use Hepworth as its bomb-proof, and doesn't have such flaws, or such thick inserts, either..

Wunda are about the best price, but look around.

The Salus ones do as they’re geared and use stepper motors to change state. Others are a heating element that warms a bag of wax, and take up to 2-3 minutes to fully open / close. You cannot use solenoids as the momentum of the water flowing in the loop has enough potential to cause water hammer, hence the slow open / close normally preferred and promoted with the standard wax heads. Closed by default so you don’t get unwanted flow down one loop when another is calling. The Salus ones are great, and automatically balance the system by detecting heat on the return pipe and that makes the actuator arrest flow, thus leaving the remainder of the pumps potential to service the longer loops which have not yet returned warm / hot water.

Always blended. yes, pump will switch off if you have a manifold wiring centre and have fitted actuators to each loop. ?.

Crossed with peter.

Every UFH manifold needs a pump and a TMV. TMV’s cannot be pumped through, they have to be ‘sucked’ on, ergo a pump needs to be downstream of a TMV in a heating setup. TMV caps the max temp the floor will ever see, I’m sure there’s a reg there but moot unless you intend to not fit one. You should not ( cannot ) rely on an external Ctrlr to guarantee that the slab / screws won’t see the max temp of the heat source, so if said Ctrlr failed, on an ASHP, you could get up to 55-60oC floor temp which will cook anything that’s not high-temp tolerant, plus it would be a health hazard ( if a toddler or elderly were to end up on it ) or if anyone walked onto it barefooted etc hence the reg. UFH manifolds need the local pump to circulate water through the loops, and the ASHP circulation pump send the water to / from the manifold. Think of it like a figure 8, with the two circuits being connected but hydraulically separate eg both pumps can circulate at different flow rates without conflicting with one another. The IVAR blending set also has an inbuilt bypass ( so the ASHP pump never sees a closed circuit ).

How are you getting on with piping ?

Maybe not. You’ve asked the question and you have your answer ?. I couldn’t find those low temp blending valves anywhere else, at a decent price and with an A-rated pump, so if you have everything else then you only need to order that and you’re done?

Primarily as max floor temp failsafe is what @PeterW meant to say Putting a zone valve in and doing as JSHarris did would be an option too, to shift the heat from the sun-baked bits of floor to the colder side of the house.

Blending valve ALWAYS. You will need a low temp tolerable one such as the Ivar as normal TMV’s very much dislike low flow temps ( 30oC and below ) but these cope very well.

Lets wait and then make some further recommendations. Your build sounds like it could easily accommodate an ASHP and it would be better suited to drive that type of heating.

Install the gas for now, and leave it all set up ready in anticipation of the fitting of an ASHP later down the road if the numbers make more sense then. If it's not a massive property you could get away with a decent high-flow combi boiler at £1500-£1800 plus fitting. Do you have rads or UFH? Most other M&E's I've spoken with still advocate using gas if it is available.... Your conscience is your's to deal with and your's alone. Also your money is your's to spend, and not others who may aspire to better things ( when it's not at their expense ). Do what is right for your budget and expected living costs, and if it becomes viable later, you or a new owner could retro fit the ASHP with ease.

You may be better off fitting smart TRV's to the rads and leaving one strategic radiator as bypass ( a towel warmer / bathroom rad possibly ). Short cycling wont kill the boiler, but it may reduce longevity. Which boiler do you have - make / model / kW? Maybe a good exercise would be to put the kitchen UFH on on its own and just sit at the boiler for a half hour or so to see just how many heat on / off cycles it does. Wait until the heating is up to temp before doing this check, as it'll be under duress whilst achieving the required heat output, which won't cause much short-cycling as that is heat thirsty, but then it'll need very little to keep it there once stabilised which is when short-cycling is likely to be at its worst. Short-cycling is caused when the boiler produces more heat ( at its lowest output ) than the heat load can absorb and dissipate into the dwelling. This is worse with UFH as the thermostatic blending valve on the UFH manifold will also refuse any temps over the set value. Typically 30oC-34oC and the boiler heat dial would have to be set a lot higher a the rads would never get warm enough if the boiler was set to match the UFH only. This is why people sometimes end up fitting small buffer tanks between boilers and UFH, particularly if rads are involved ( eg two different types of emitters each requiring two different temps, sometimes at the same time, and from the same heat source ).

I think the rads are coming on as a byproduct of the UFH calling the heat, as there’s appears to be no way that this is set up to arrest the flow of heated water to them ( if there’s no ZV fitted ). When rads are deselected, a ZV should shut to isolate the rads so the UFH is the only place heated water gets to. As I’ve said, this would promote short cycling so maybe this was set up ( albeit inadvertently ) to use the rads as a bypass when the UFH cannot dissipate the heat output of the boiler on its lowest output.

Yup, likely the rads, possibly another UFH manifold. There should be at least one ZV at the boiler to allow just the UFH to run, bu this may have been deemed a correct installation to allow the rads to run simultaneously if to stave off short cycling when the UFH load is minimal.

Do all the UFH loops get fed from that one manifold?

Hi. Looks like no 2-port zone valves have been employed to split the heating zones apart. Do you have any of these types of valves anywhere?

Leave all the fillers out and just foam / bond EPS insulation to the high points. That'll allow air to shift behind the insulation and keep condensation in the middle from being so problematic. Buy some sticky neoprene 50mm x 3mm insulation 'tape' and do the 3 sides visible of that 40?mm box steel, as that'll be your biggest cold bridge from outside to in, doubling up on the very inside face(s) only. Foam all of the corners and make it draught-proof as best as you can, but still maintaining clear open ends for the sheet profiles. Them being mounted horizontally makes this airflow a bit less 'natural', but shouldn't be a problem. Use foam / other suitable bonding agent and hold the sheets of EPS in place with 8x4's and some temporary battens, like shuttering. Try not to let what you store touch the outside walls and that will promote better mould prevention, but ironically you'll probably need to have some ventilation there in the summer to stop it sweating. Have you insulated under the floor yet? If not, you'll need to address the junction where the walls meet the floor as that'll be the biggest problem area if left unaddressed. Foam will be your friend here, just choose low expansion grade and minimise the wastage / nuisance contamination from over expansion. I don't really see the point in going to the expense of PIR tbh. EPS is pennies by comparison,.