Nickfromwales

+1. Heating the bathroom with electric UTH ( under tile heating ) will be bloody expensive to run! Have the UTH by all means, but not as your primary heat source.

Yes, some find the Grundfos noisy but I think they must not be turning them down to the lower setting. They get delivered set to run at max IIRC for purging / commissioning so need to be set up properly for the particular duty.

Good. Ask them if they can do a screeded pitched floor and do away with a lot of the expense. All you need then is tanking and a waste / trap. Give them the money you would have spent on the tray, and I assume you'd be screeding anyways so 2 birds ( lol ) one stone.

I thought it was 'all' of them

NO and NO....it's what holds the ring with the teeth in place!! ? Without that you'd better have good buildings and contents insurance. It ONLY self tightens when the fitting compresses itself back against the flat shoulder provided by said "irrelevant twisty bit". The barrel inside the fitting is parallel edged, NOT tapered, and nothing in there is self-tightening. I suggest you buy one and take it apart and see for yourself before offering any further assumptions. Better still, ring JG and ask them how 'irrelevant' it is and get it straight from the horses mouth, or maybe they can save themselves £m's of wasted parts and labour adding it for no reason and do what Hepworth do...... They will tell you how important that 'twisty bit' actually is of course .

You offering to go there and do it? ? If not, then who is? If you can do it yourself, then yes. If not, then is it 'really' a nice quick job? @canalsiderenovation, how brave are you feeling, and how much of this are you willing to DIY?

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.