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Firstly, I really appreciate everyone's input - thanks. I have to say I am a little lost when it comes to the intricacies of all this - I couldn't tell you without looking it up the difference between an S and Y plan for example so bear with me! It is from Alto as you all seem to know. It has finally arrived after a long wait and I will have got a recommended plumber ready to install it. I am not fully confident that left to their own devices the plumber and electrician will install it to allow for cooling and so I would like to have a solid understanding of the necessary steps needed to succeed. It is a 150l pre-plumbed standard cylinder EHPT15X-UKHDW that accompanies the 6KW Ecodan and FTC6 controller. I have 4 UFH loops downstairs that will be one zone and radiators upstairs as a second zone that are sized for low temperature so can run at the same temperature as the UFH (I assume that is the case as it is well insulated, airtight with MVHR and initially I considered not having rads upstairs but have them partly because without them I wouldn't be eligible for the new £5k grant). Currently no PV or plans to do so. I can't quite grasp the mid-position v. diverter issue and how it relates to S or Y plans (is S/Y plan another one!?). From what I can gather the schematic they suggest is a Y plan (the 3 port being the Y) but you are suggesting that S is needed for cooling. By mid-position are you referring to the Y plan and for S plan I need the diverter valves? One thing I don't know - is the low loss header something not likely to be included in the kit (I can't see one) and so the choice of LLH or buffer is still open. Looking at the diagram in the manual for cylinder it seems to specify a LLH (number 22 in the picture below). I am slightly worried once I suggest the buffer alternative that Alto will say that isn't what Mitsubishi specify so they can't recommend it/sign it off. I'll attach a couple of pics of the cylinder down below as well.

As the title suggests - would this schematic specified for an Ecodan PUZ-WM 6kw ASHP and pre plumbed cylinder with an FTC6 controller work for cooling? I seem to remember reading past posts that suggest something different needs to be done (is it to isolate the cylinder when working in reverse?). A further point - I know that some think 3 port valves the work of the devil! Why is that and what is the alternative? Thanks for any advice.

It’s for a small dwelling with 11 circuits (so far!)

Anyone got any recommendations/preferences for good quality CU? my electrician used to use MK but says quality has gone down and are looking at contactum though I had less good experience with them a while back (before the days of all metal). I have liked hager .

I don't see the point of adding anything to a lime render - it is going to set fine. You could also consider just getting some hydraulic lime and sand separately as it tends to be a lot cheaper. But if it is just a small section may be easier to go for the premixed bags.

Hydraulic lime (which is what you want to be using, not hydrated) already sets in damp conditions. In fact it is best if it does not dry out too quickly which is why when you are working with hydraulic lime you should always damp down the render/mortar on days after applying it. It is the chemical reaction with the water that makes it set hard. So I wouldn't see any need to add pozzolans to the lime. Rendering with lime is not really any different to rendering with cement (except plasterers who aren't used to it might say otherwise) - you just have to make sure the walls are well damped down before application (especially in summer now) and are kept damp for a while after (you can spray it once a day).

Hadn't thought about this though I am hoping to get away without it since the isolator for the ASHP will be very close to the wall penetration so I presume I can get away with some suitable conduit.

I am installing a 6KW ecodan PUZ ASHP. Looking to 1st fix the main cable to the ASHP. It is a run of about 12m with insulation on one side of cable only. In the manual it says it says 'Outdoor unit input capacity Main switch (Breaker)' as 16 A and minimum 3 x 2.5mm cable. Does that mean the earth needs to be 2.5mm? (assuming it is one of the 3 cores) Part of me thinks I should just put in a 4mm cable but I don't want to over specify unnecessarily. Any one got an opinion?

I’ve ended up using some left over air tightness tape around the sockets. Has to be better than nothing. presumably it is the airborne transmission of sound this is dealing with mostly.

interesting - hadn't come across that. presumably you mean something like this: https://www.insulationexpress.co.uk/speedline-acoustic-putty-pads though I can't seem to find it in smaller quantities.

I have a 70mm thick stud wall to insulate for sound. I also have a lot of 75mm rockwool sound insulation. Is it better from a sound point of view to just fit the whole 75mm in or I could easily cut in half for 37.5mm thick with an airgap? I seem to remember it is best to have an air gap and if I slice in half it will go twice as far. Presumably 50mm with a 20mm gap would be best but trying to work best with what I have.

thanks all. Just had electrician who will be signing off round and he explained things nicely. Its all going to be easier than I thought!

Lighting for downstairs is being done with circuit wire being brought into the switches not using ceiling roses. Essentially I'm using 1.5mm twin and earth for the main supply and 1mm to any bulbs. It runs radially from switch to switch. For the landing light I have a switch downstairs (S1) and a switch at the top of the stairs (S2) which need to be arranged in a 2 way fashion. Do i need both a 1.5mm twin and earth for the supply from S1 to S2 AND a 3 core and earth from S1 to S2? Or can it be done with just a 3 core and earth from S1 to S2? Thanks

Should fire alarms be on their own circuit? I presume so but presumably there is some benefit to having them off the lighting circuit as it makes it harder for an inhabitant to turn off the alarms due to nuisance beeps.

Why are you wanting a gshp and not an ashp? Lot more effort for the gshp for little extra benefit I would say. what is the power consumption of the house at the moment (heating and water)?

I like the idea of a couple of USB sockets higher up - am i right in presuming that one can run a couple of those as spurs off the main ring circuit?

Well at the moment I have a plug socket next to my bed behind a low cupboard and if I wanted to plug in a usb cable the cupboard needs to be 100mm away from the wall which isnt ideal! I like the idea of another socket to the side of any table. OOps - cant work out how to delete a post!

I guess the problem I have with my current bed is that to use, say, a usb charger the set of draws I have next to the bed has to be 100mm away from the wall which is just weird. I guess the old 4 way extension to the floor is another option! I like the idea of an extra plug to the side.

Do you mean you have a small gap between bed and table? my problem with that is that bed size might vary and I would normally put table/cupboard right next to the bed. I can see it working with a table but if a cupboard then everything starts sticking out!

I need to plan the position of sockets in the main bedroom. Not a huge room but there is an obvious place where a double bed goes and it would be useful to have sockets somewhere either side. A problem I have run into the last place I did was that if I put sockets say 500mm off floor and near the bed that side tables/cupboards can easily make it awkward to use these sockets. Any suggestions? Go above table top height? Go wider so avoiding any potential bedside furniture?

I think I asked a while back about this but cant find the thread. I'm wondering if my plan for alarms is acceptable. Its a small barn conversion (70m2 total) with an open plan downstairs (except for lobby/toilet) and 2 beds/bathroom/landing upstairs. Looking at the plans below I am planning on a heat alarm where the 'h' in kitchen is (downstairs - first image) and a smoke alarm in the landing at the top of the stairs in the second image. I am thinking that is sufficient - would that be correct? Is there a minimum distance a heat alarm should be from a cooker? Also - am i right in thinking it should be wired in 3 core and earth (1.5mm) radially on its own circuit?

Does anyone know how well insulated they are? I mean if it was turned off how long before it reaches room temperature?

What would the temperature of the water be in the morning if you turned it off overnight? Room temperature? Surely it must be wasting energy to have it top up the heat overnight. I know nothing about Quookers and I can see the advantages of leaving it on (especially if that is how the manufacturers expect them to be used) but I can't see how you get round the point that it must be using more energy than needed if left on overnight.

Seems interesting and well thought out. Be interesting to know how many land drain pipes they have coming out through the foundations and where it all goes. I'd also like to know the u value of the 250mm expanded glass - can't remember off hand what it equates to but I suspect not nearly as good as a similar thickness of EPS (and they also have a 100mm layer of sub base above the expanded glass to warm up)