ProDave

Your pictures are only tiny thumbnails not the full picture. You would need to start with a larger frame and cut it down. You would probably be just as well making the whole thing from scratch with stock timber.

The key thing I get from this thread is in future ask the forum BEFORE you start a job, then you would have known to get the pipes 150mm, bin the cranked bits, and drill the holes in the tiles slightly over size to give a bit of wriggle room. If you have access from behind, I would remove the pipes and uses something like a dremmel to grind a bit of tile away to elongate both holes by 3mm so you can get your 150mm spacing.

Buy a proper roof ladder. And don't chuck you old dish in the neighbours garden.

^^ @Onoff gets bodgit of the week award.

I doubt the cranked bit is the right size or has a tapered inlet for an olive. And if it could be engineered to work, it would still stick out to far and not get covered by the cover plates. Have you cemented the pipes solid in the wall then? The idea is there should be a bit of slack in them so you can set the final spacing then screw the brass bits to the wall at that spacing.

The fitting you have is a front mount fitting often championed on this forum. The idea is you adjust those for final spacing from the front then screw them to the wall and the shower bar fits straight onto those. The cranked fittings you have screw into a female BSP fitting. That is an alternative way of doing it, you fit the female BSP behind the wall at roughly the right spacing and used the cranked adaptors to make the final adjustment. the two are not compatible. Apart from anything else if you could use the cranked fitting like that, the bar would be a long way off the wall.

https://www.barbourproductsearch.info/vaillant-arotherm-split-1-0-lr-1454128-file081541.pdf Page 3 tells me how silent it is (sic) It shows the outside unit contains the fan and the refrigerant compressor. I would expect this bit to be the noisy bit, probably just as noisy as a monoblock unit. The inside bit is just a heat exchanger, expansion vessel and WATER circulating pump. 2 things spring to mind. Get them to power up just the water circulating pump in the inside unit (may have to temporarily wire it to a bit of flex and a plug) to see how much noise actually comes from that. I suspect not a lot, but it is a test that needs doing. As the pipes between the inside and outside units contain refrigereant gas, have they actually been piped with any flexible sections? is that indeed even possible? If not a least a full turn pig tail on each pipe to try and isolate noise from outside to inside. You could also temporarily disconnect the internal water pump and try running it. It probably won't run long before throwing an error but it might run long enough to see if disabling the internal water pump reduces the noise or not.

Can you post the full model numbers of this unit please?

The on/off thing in the night. the manufacturer should be able to advise on that. My own LG ASHP does a similar thing. at night when "off" if it senses the water temperature in the outside unit is <10 degrees, it will turn on the circulating pump to run the water around the system. Essentially it is drawing some heat out of the warmer pipes in the house to keep the water temperature in the outside unit above 10 degrees. Now in my case it is just the gentle hum of the water circulating pump and for perhaps 30 seconds each time it comes on. The colder the night the more it comes on. Only the manufacturer could change that, it is not even a documented thing, just something I have observed, and there is no setting to alter it. But if it really bothered me, i could disable it by putting the whole thing on a mains timer to cut power off overnight. I personally think it is an unecessary function, the water has inhibitor / antifreeze that should be good to -10 degrees, so turning on at +10 degrees is way over the top. I would at least like to adjust the trigger temperature down close to zero (where the antifreeze would still be protecting it) Next time you have a visit you need to ask the "engineers" to power up the individual components to see what is really making the noise. It should be very simple to temporarily power up the water circulating pump for instance and see how much that is contributing the the noise. At the moment you don't really know what is making the noise, just "something in that box"

When you instructed the contractor to install a system for you, did you at any point tell them it must be somewhere between silent and almost inaudible inside the house? If not, then I doubt you have a leg to stand on. If I had been asked to design a silent system, it would be a monoblock unit, placed further from the house, preferably by a wall without a door or window, and all necessary water circulating pumps would be in the outside unit.

What do the instructions say about noise levels? Has anyone measured anything with a sound meter? If the noise is within manufacturers spec, there is nothing they can do.

Who advised you an ASHP was the best form of heating for an old leaky stone cottage? They work very well in a modern well insulated house where it needs a low level of heat input and does not cool down quickly when the heating goes off. Ours turns off at 9PM and stays off all night. i still don't understand where your noise is coming from? is it the heat pump outside making the noise and transmitting it through the pipes? If so flexible pip sections where it enters the house should stop that. Or is is a circulating pump within the house? I had issues initially that the under floor manifold pumps were noisy, until I changed them for better Wilo pumps. All I can suggest is you get the installers back again. If you paid one price to one company to install a complete system tell them it is "not fit for purpose" and you want it removed and a full refund unless they can make it operate properly and quietly.

I have seen some that make that mistake, and then carry on and drill out half the joist so the light can still go in the "right" place. No don't do that.

I would put the DPC under the bearers as well.

wedge something in the trapezoidal hole and then apply some "load" to it and see if it rotates when driving a load. Can you see anything in the gap between the front and the black "plate" or is it totally enclosed? It does not immediately look like that is meant to dismantle.

Video won't play (probably my poor broadband) What "teeth" are you referring to? those 4 prongs? Can you post a picture of the part the knob mechanism mates to? What's that slightly trapezoidal hole just down and to the right? Is that where a spindle engages? if so that should turn as you rotate the knob and there is either a gear or belt between them.

Tell me about it. I am trying to get a temporary habitation certificate.

It's a mechanical problem then. the basis of all electric showers is the heating power remains constant and you adjust the temperatue by adjusting the water flow rate. Running briefly hot then going cold is usually a sign of too little flow, it overheats and shuts off the heater. Some showers have a little toothed belt to connect between the knob and the actual flow control, check that has not snapped. Can you post a picture of the mechanical bits around the temperature knob?

Do you have a multimeter to take some electrical measurements? Does the water flow rate vary as you adjust the temperature knob?

I ruled out GSHP due to the cost of the pipe and brine to fill it with exceeding the cost of the HP. Even with my own digger at the time so install would have mostly just been time. Also the noisy bit, the compressor would be inside the house with a GSHP. I settled for an ASHP instead, a lot cheaper and the noisy bit is outside. The small extra efficiency of a GSHP would never pay for the extra install costs

Hi and welcome. sounds a great project. I would perhaps consider a beam and block floor with TF walls on top of that. It gives you a bit more resilience if you got your sums wrong and you get a flood higher than expected.

In the last house I used wooden window boards that warped like bananas. I wanted anything but that this time. Most living rooms and bedrooms have window boards made of left over engineered oak floor boards. Bathrooms have window boards made from offcuts of multipanel. Kitchen has granite window cill to match worktop and a granite upstand Utility room has a slate tiled window cill using left overs from the slate floor tiles.

Having lived in a 1930's solid wall house, I know they leak heat like it is going out of fashion. I would be very surprised if you can get a 1930's house good enough to not need upstairs heating without adding internal or external insulation to all the existing external walls.

That's a lot of money for not a lot of extractor.

What is the floor presently? I have 22mm P5 chipboard, an Impey Waterguard membrane (it's a wet room) and tile onto that. The Impey membrane is a decoupling membrane that makes it okay to tile onto chipboard and has negligible thickness. The tiles are probably about 15mm above the flooring max, about right to meet with a carpet and underlay at the door. P.S. Before I was told such things are wrong in a previous house I tiled the hall and kitchen direct onto bare P5 chipboard with a flexible adhesive and never had any problems in 17 years.