Nickfromwales

If this is internal, then I'd also say run 28mm pipe ( copper or Hep2o ) and insulate yourself. As the delta between the pipe and the ambient temp of its surroundings are minimal, there is no real reason to go for pre-insulated afaic. Also, the pre-insulated pipes have a bending radius of around 1m, varies with external diameter based on how thick an insulation you went for, so near impossible to navigate tight bends also. I am using Primo Uno on an upcoming ASHP install where the runs are circa 30-32m from the heat pump, so I'm maxing out the insulation levels by running 2x Uno with thickest insulation available vs 1x Duo with limited, albeit still very good, insulation. For you, deffo stick with regular pipe and if you use Hep2o you can go very long distances with no joints, and then just slide un-slit sleeves of pipe insulation down each one. Then clip the pipe and insulation into place with either plastic waste pipe clips or powder coated all-round band ( from electrical merchant ).

Hi, and welcome. Some good choices there already so you're off in the right direction On this point, just remember that a typical 4kwp system will absorb around 28m2 of roof space, so, for eg, if your roof covering is costing £100/m2 you'll have a hypothetical credit note of £2,800 gifted to you from the savings of not roofing that area. Maybe that helps to at least get panels on the roof and DC cables in at the time of roofing, with a view to connecting the remainder of the system downstream / when budget becomes available.

Good prices and good kit the last time I used these people; https://www.heatershop.co.uk/electric-underfloor-heating-uk

OK. With an ASHP there is a 3 way DIVERTER valve, and with a traditional heating ( aka S-plan or Y-plan ) there would either be a 3 way MID POSITION valve. The diverter will ONLY allow heating OR hot water, eg never the two together, as with an ASHP there are pre-set temp changes per the duty ( say 40oC when diverter is flowing to heating and then 55oC for hot water etc ) so if I read the above correctly there is still flow going to the rads when heating is selected, and the rads gets hotter during hot water 'mode', and this is a brand new sealed and pressurised system? That tells me that the 3 way valve is either plumbed in incorrectly, or "passing". The 3 way valve has deffo been replaced and you witnessed that happening in person?

He's talking out of his arse. I've fitted new heating systems ( and fixed older ones too ) for north of 25 years, and what he says is a crock of crap. I've converted 50 year old systems from gravity hot + pumped heating, with pipework that looks like a rat-run with T's here there and everywhere, to new sealed and pressurised S & Y-plan and I've never had this issue. If the 3 way valve has been installed correctly, and more importantly WIRED correctly, then zero heat should get to any of the radiators. That would only be applicable if it were a gravity DHW scenario where the heating would get reverse convection flow to rads higher than the heat source. @graham1 The quickest way to solve this would be at ask your installer to put a gate valve in the flow to the rads, between the zone valve and the first rad, and then to close it. If the issue remains, further investigation into the plumbing layout is needed. Is this a 100% new install or a retro-fit new boiler onto existing pipework and rads?

OK. So assume that at over 4kwp you had to request permission from the DNO? Bear in mind that anything A/C coupled that is a generator adds to your total grid-tied generation / output, so, for eg, if you had a 4.8kw battery system and your 6.2kwp PV installed at the same time, you'd have been then asking for permission to connect 11kw of grid tied 'A/C coupled' generation. I'm not 100% sure where anyone stands adding this retrospectively or DIY / other, but it is ( technically ) something which you should be asking for permission to connect / add AFAIK.

If it’s doesn’t compress, fit the foam expansion skirting afaic. It’s an expensive mistake if you find it was needed.

Glasses it is then 🤔🤓 I bought this one, apologies lol. Was the cheapest I found without ordering online. Select between 750w or 1250w or both for 2kw.

That doesn't have a timer. Plus, I wanted to go and pick it up and TLC had stock for immediate collection.

https://www.tlc-direct.co.uk/Products/HE2CH.html?ad_position=&source=adwords&ad_id=398484945570&placement=&kw=2kw convector heaters&network=g&matchtype=b&ad_type=&product_id=&product_partition_id=&version=finalurl_v3&gclid=Cj0KCQiAip-PBhDVARIsAPP2xc3khvVfd48mNNgTValG50Kyv4thZANH9mbEjeij0EZKwHF5aat3PqYaAmcVEALw_wcB Cheapest I found. Bought one yesterday and very happy with it for the money.

3 days minimum, unless you're happy to put 18mm plywood sheets down and police the activities. Even then this is not a great practice....

So you’ll be fitting whatever she says then

Radio linked systems are quick and relatively easy to install, and just take power from the nearest source eg light fitting with loop-in's, or a socket outlet with a fused spur connected for a 3a/5a supply. Basically you can pinch power from anything as long as it's fused down accordingly ( if a higher power circuit than a lighting supply ). @ProDave, can folk DIY?

I am also a tiler ( past business for over 20 years fitting high end kitchens and bathrooms ) and have never used a cement board / backer board, unless the client has bought them and has insisted, and then I’ve charged for the total pita they are to cut and finish. I do not like these boards as there is zero give and they do not confirm to the substrate well enough for me. The screws are everything in terms of purchase, and you either fit screws every 100mm or at 200mm and bond the boards on with Sikaflex for belt n braces. MR ( green ) PB for me on every single job, and tanking in every area of concern / wet areas. No leaks, no comebacks, and just about to become 25 years of doing them with all my customers still having my mobile number which I’ve had from day 1.

Don’t avoid sockets, just create a robust method to install, so as to reduced / eliminate infiltration, and put as many in as you like. Use fast fix boxes Link and just feed the cables through 30mm holes dead centre of each socket box location. Then you use a pad saw / other to cut out ONLY the amount of depth you need, through the PB and into the PIR. Allow an extra 5mm of depth for foam to expand into. Once the wall is prepped for the fast fix box to be installed you can use a blank module plate Link as a dummy socket face so as to be able to temporarily fit the 2x plate screws and tighten up the fast fix box ‘wings’ and then level off with a small boat level. Fast fix boxes are loose until the plates are fitted and the plate screws fully tightened Then you can use a foam gun to fill the cavity at the sides / rear and the hole the cable comes through for a bombproof install. Use air block foam such as Illbruck pro Link and that will also create a very good mechanical fix too as it cures significantly firmer than builders / typucal expanding foam. The OSB method is a no brainer, it just means fitting regular PIR sheets, then OSB over those, with long screws through for extra purchase where you predict there will be known loads affixed to it later, then the PB ( in each critical area ).