Nickfromwales

With a dual stat setup and an oil boiler, you’d struggle to not get DHW almost on demand tbh. A TS is a beast for producing DHW, and the heat goes almost directly in / out. With an oil boiler you can size the TS smaller and it will then recover faster, but if ST and / or PV are present on an install you’ll typically want to size a TS significantly bigger to harvest that ‘free’ energy. A TS will give a diminishing output vs an UVC, so needs careful thought and consideration, but if @Gone West has oil as a parachute, they’ll never ever be stuck for DHW with a TS. A 15-20 minute burn from the oil, from cold, and you’ll be able to jump in the shower, assuming a 200L TS vs 21-26kW boiler. To maximise the performance, I always specify a 28mm high recovery DHW coil with my TS installs. Trevor at Cylinders2go can get pretty much whatever you want specc’d / made to order.

Thermal store instead of UVC? Omits the coil and it’s inherent complications in utilising the oil boiler ‘properly’. I very rarely couple an oil boiler with an UVC for this exact reason.

Yup and yup. Always used this supplier and great service every single time. Got 5 of their setups to order in the next few weeks for 3 new full passive builds I’ve got on atm. Very happy with them, supplier and product, and prices are good enough for me to not look elsewhere.

Wet and dry vacuum to suck out the majority, and introduce some air pockets, and leave both ends of the loops just taped over loosely. With walls and roof on, you’ll be fine with that measure for mitigation. Is the garage door on, or can you OSB it to stop the winter wind blowing in / around?

Gravenhill, 1st of the 2 plots done iirc. Was a mess.

Looks busy, but the plumbing looks neat / well executed. Too much going on there to comment tbh. “Carry on!”.

The 27kW Stiebel is a very impressive unit. I’ve a 27kW gas combi, and there is very little in it. I’d be quite happy with that 3ph heater in my own home. 30kW instant is just too big, requiring a jump to 40a/ph. 32a/ph on the 27 is fine.

This is how I work with this type of system. I run more of the counter ( service ) battens horizontally, so they can be fixed side on thus not needing to fix through the membrane, and then the boxes get drilled and screwed up and down into the horizontal timbers. The Egger board was installed to take the wall mounted TV’s, so they could be fitted with the correct depth / length screws so again the membrane didn’t suffer damage from any such retrospectively installed equipment. Injecting 330 foam all round the Egger board would offer further insurance. The sparky should drop down and go through to the next room in the joist void imo, or create a penetration with a conduit which can be filled with Illbruck 330 foam and made airtight accordingly. As said, you must lead on this, as most trades still have little to no experience with airtightness disciplines / products etc, and you should be prepared to provide them with the correct foam / tape etc if you want this doing correctly.

If recently refurbished, do you know if they let the screed dry properly before the floor went down. A day per 1mm is the norm. Maybe they’ve put the floor down too soon and water is still evaporating. Either that or you’ve got a leak. Is it a sealed and pressurised heating system? If so, there should be a pressure gauge ( on the boiler perhaps ) that will tell you if the system pressure is staying in the system.

When I was called out to a job where 3 of these identical pumps were installed I contacted Grundfos as all 3 had seized impellers. This was a bit over a year ago. When I was sent a pdf for the recommended installation positions it was defo showing not fitting them ‘upside down’. The reason was that air bubbles would constantly be pulled downwards into the pump body but would try to rise to escape, thus causing issues with pump longevity. In 3 decades of heating and hot water installation I have only ever seen 4 pumps fitted this way. All 4 were kaput. Other pumps I’ve installed ( in what is an industry recognised orientation ) ‘the right way up’ have been in in some installs for coming up to 20 years. I can’t pull up the info, and cannot argue with the literature you’ve posted, but no plumbers I’ve ever worked with / for would accept a circulation pump installed this way. The way your setup is installed does not promote self purging of air, and is not as the manufacturer of the manifold recommends you install it. Instead it promotes air being drawn down into the loops where it will eventually sit and cause air locks. I concede to your posted info and confidence in this being fine.

@PeterW I used the ° symbol 😇. “I’m a real boy now!”

Indeed. So, do NOT remove the mixing set, as that is there for failsafe at the very least and it is a bad idea to remove this and then rely solely on the heat source to deliver safe and reliable flow into the floor. Also, your pump being upside down is not great. Look at the manufactures installation guide and that setup has a big ❌ against it as it will cause the pump to wear out prematurely. The plumber detached the pump head and rotated it 180° to make it look right, clearly demonstrating that they knew it wasn’t done properly.

There are manifolds to do this out of the box.

We did speak previously, about you not drinking before lunch?

How about a key, which is physically compatible, can be fully inserted and left in the “hole”, which has a bit of felt / neoprene as a plug to stop the draft…………but is an uncut blank from a locksmith ( ergo it cannot be used by a burglar to unlock the door )?

That’s what we’re installing next week ( Zappi 3ph 22kW rapid ) and have installed a 5-core SWA to surface mount in the new double car port. Why are you getting involved with this / speccing cables and not the installer / sparky?

Perimeter ( expansion ) insulation is only really necessary on a heated slab? A bit OTT if it isn’t heated IMO.

Liquid DPM first, and flick some sand over it whilst wet to provide a key. You don’t want to bring damp up to the surface and then try and hold it back from there, far better to keep it out of ( below ) the new filler material.

Those setups can only be plumbed it as a left handed arrangement, whereas your plumber has gone against this for possible convenience of plumbing it in..... And the isolators ( red and blue valves ) should be between the rails and the mixing set, as per above image, eg so you don't have to drain down the loops to service the mixing valve etc or the pump and then risk getting unwanted trapped air getting into the rails / loops.

I'd be more concerned as to why the input group and the pump are completely the wrong way around?!? The pump is pumping upwards, and the words IVAR are upside down, showing that the water that should be being 'sucked' through the input group is in fact being pushed backwards against it. Like that.

Not sure, but cowboys are usually found on horses

From a discussion about my frozen sprouts defrosting, to wellies. “Only possible on da good ol ‘hub” lol.

Those ones are only good if you get yourself in deep shit with the DNO……

Depends on the number of inputs and the max loading of your inverter. Best to speak to their tech support dept tbh, vs risk damaging anything.

You don’t need one? You just flick off the isolator in the CU to simulate a power out / work on the domestic electrical system. Needing to isolate the mains to the CU is something you’d be engaging a qualified sparky for, and they’d just snip / retain / reinstate ( so it looks intact ) and move on to the next job.