jack

Welcome Carl. Could you provide some more info? Do you have a plot (or house that you'll be demolishing). If so, do you have plans/designs? [edited to add: ha! cross posted with @ProDave]

As above, I used 50mm polypropylene drain pipe. I then ran 28mm Hep2O pipe for the actual ASHP connections. If you use plastic, you must be sure to use the type with an oxygen-proof barrier. This approach was relatively easy for us, because our runs were completely straight (except where they come out of the slab in the plant room), and ran within the EPS under our slab, so didn't need separate insulating. Where is yours running? Underground?

I think I used 50mm polypropylene drainage pipe for mine. Worked okay. How are you planning to insulate?

Nice work!

We had a strict no-smoking/vaping policy inside the house, and oddly enough most of the tradespeople we had onsite didn't smoke. I was also surprised to notice that "builders' tea" is now far less likely to involve sugar. I'd say 90% of the people we had onsite took tea with milk and no sugar.

Did you keep the receipt? If so, you should still be covered through whoever you bought it from. I think registration is for the manufacturer's warranty, which is separate to your ordinary consumer rights (I'm not 100% sure of that - maybe worth a bit of research).

I do the same, but it still stinks. No-one else seems too worried by the smell - I just have a delicate nose

I open a lot of windows so that the acrid smell of burning oil/fat leaves the house as quickly as possible. It's a difficult smell to describe, but I find it extremely unpleasant.

Until you've completed it, there's still the possibility of leaks through the unlined areas. Are all your windows and doors adjusted to be maximally airtight? I can't say we've noticed any sound at all from our build-up (much like yours: airtightness membrane over 22mm OSB walls, held on with battens to form a service void). If it's anything like the stuff we have, I doubt a bit of flapping will do it any harm. It's seriously tough stuff.

We'd have done the same, but the way the plot is laid out meant there was no obvious place to put a caravan that wouldn't have impeded access. Agree completely about being onsite - as well as being available to oversee things, I'd have gotten a lot more done had we lived onsite rather than 6-8 mins drive away.

We did something similar. Bought a bungalow in a nice area (literally the worst house on the street), largely surrounded by much more substantial houses. We got an offset mortgage and put money into the offset account to reduce the interest to zero. We then drew down against the offset account as we demolished and rebuilt. We probably breached our contract by demolishing without the mortgage company's permission, but hey, they now have a mortgage against a much more valuable property! Our design and planning took well over a year, then it took a few months to get organised and move out into rented, followed by a year from demolition to moving in. I agree that if you rent you should do so as nearby as possible. Ideally, you want to make an appearance on site every day, and ideally at the start and end of the day.

Welcome @Clive Chitty, and thanks for such a comprehensive first post.

22mm pipe has around 380mm2 cross sectional area, compared to 80mm2 for 10mm pipe. Ignoring friction, you therefore need nearly 5 times the flow rate to achieve the same water speed in 22mm compared to 10mm. The flow rate is set by the tap. Since the tap doesn't have a cross sectional area equivalent to anything like 22mm pipe even when it's on full, water will necessarily move slower in the 22mm than the 10mm for a given (relatively low) flow rate.

That info would have been useful about 18 months ago! It just seemed like a lot of complication and cost for a small return at the time we were planning it. With hindsight, perhaps we should have plumbed return loops, especially to the kitchen, but it isn't really that big a deal. If I really need hot water in a hurry I can use the boiling water tap and add some cold water if I need to drop the temp (not recommended as an approach for handwashing!)

I did say "first world problems". Would it help if I added a hashtag? I just timed it - 25 seconds to full heat. As for your shower scenario, I lived with exactly that situation for over two years in the bungalow we demolished to build the new house (and the rental we had for a year during the build wasn't much better). The water pressure was so low that we gave up trying to shower and instead spent 10 mins dripping enough water into the bath every day to have a wash. Reused the bath water too, because there are only 24 hours in the day, which is more than it would have taken to run 4 x 3" deep baths. Oh, and I didn't mention the 45 second wait for hot water at the sink in the main bathroom of the new house. Weirdly, it's the only tap upstairs that has any problem - the shower in the same room runs hot in 5 seconds. It's actually one of the closest taps to the DHW tank as well. I can only assume it's taken via some circuitous route for some unknown reason. And finally, my answer wasn't to whine about hardship. Someone asked about plumbing and specifically mentioned long runs. 20 seconds IS a long time to stand there with the tap running before you can do a quick hand wash in warm water. I'd be more accepting of it if the house were old and that's how the plumbing worked, but we spent a lot of time, money and energy building a new house, and this is one of the (yes, minor) things that irks me about the result. If I hadn't yet done this and were about to make a decision about plumbing, I'd be interested in hearing what others would have done differently.

We have this problem with our kitchen. It's the one long run in the house, and it takes (guesstimate) 15-20 seconds to run hot. Drives me mental, because you can't do a quick warm hand wash or hot wash of dishes. First world problems, I know, but if I were doing this again I'd consider a local instantaneous heater at this point. The alternative is a pumped loop, but I didn't want to get into all that extra plumbing, equipment and energy loss, especially in a well-insulated house.

Interesting Toolstation is so high. I'd be curious to see what format the survey took.

Link no workee for me

We also didn't pressurise. The only leak we had was the poor electrician nicking one of the pipes with a screw while installing some protective steel around a floor box when our concrete overlay was being poured.

I had a similar problem with some Dell laptops that were bought for a small business I was involved with about 10 years ago. A known problem with overheating caused the graphics chip to fail, often when the machine was 1-3 years old. They eventually extended the warranty for domestic customers, but refused to do anything about it for business customers at the time. The other problem was that the repair didn't actually fix the problem, so they tended to fail another 1-3 years later, usually after the extended warranty had run out. I was put through to some utter cretins in India who basically laughed at me and told me to take it to court if I thought I had a case. They were right, in a way. I didn't have the time or inclination to fight it. I left the business shortly afterwards, although not before we'd bought a large stack of laptops from another vendor. I've never bought a new Dell machine since, and I never will. They lost business worth well over £10k over the refusal to repair 3 laptops. Great business! I've now had a further reply from John Lewis: "Thank you for your email regarding your recent online review.I can confirm that you can view the Terms and Conditions on writing a review at the following link:https://www.johnlewis.com/customer-services/information-about-our-terms-and-conditions/terms-and-conditions-for-ratings-and-reviewsWhen you did the review online the Terms and Conditions are there for you to view and agree to prior to submitting your online review. If you require any further information please do not hesitate to contact us." The terms give them the right to refuse to post any review at their sole discretion, without reason. I can't see how that's anything other than hugely misleading - people reading the reviews on the website aren't led to read the terms and conditions. I think it's fair to assume as a reader that any honest review will be posted, but that clearly isn't the case. A couple of reviews on Trust Pilot also mentioned that their reviews had been rejected. It scares me to say that I trust now Amazon a lot more than I trust John Lewis! Annoyingly, that's the entire response to my last email. It seems they've lost interest in actually dealing with the "unsafe" product they were so worried about yesterday! More angry emails to be sent...

Ah, makes sense, thanks.

Am I right that the capacitor is just providing a lower impedance path for the induced current? If so, I assume that means it consumes at least the same amount of power this way. Seems unfortunate that there's no easy way (other than better circuit design) to avoid this continuous energy leak.

As long as you aren't in a tearing hurry, and postage isn't too much, order the minimum you can get away with and then do a follow-up order once you've started installing and can see exactly what you need. Tight fisted is good. I reckon we wasted £200+ on bits and pieces we didn't need. I can't even give them away, as it's a bit of an unusual duct format.

Can't solid-core doors be trimmed by that much? The bottom edge would likely then be end grain, but is that the end of the world in that position (genuine question)? I suppose the risk is cupping or distortion due to the lack of end piece. We bought plain (primed) solid fire doors locally from somewhere like Benchmarx (or maybe one of the big builders' merchants) and I was amazed at how cheap they were.

So the saga continues. I wrote to customer services asking for their reason for rejecting my review, and asking for a copy of their policy for posting online reviews. I've just received a reply. The policy question has been ignored. This is their reasoning for not posting the review: "I am concerned to hear of the issues you have experienced with this item and sincerely apologise we were unable to approve your review. As your review made reference to the safety of the item, which is specific to your item caused by a fault, it did not accurately reflect the quality of the item." Just extraordinary. This is Trump-level reasoning. Incidentally, a company I recently bought something from asked me to put a review on Trust Pilot yesterday. While there, I checked how John Lewis fared. Surprisingly, they have an absolutely horrific rating of 1.5 stars. They are close to last in nearly every rating category: Categories John Lewis is ranked 102 out of 103 in the category Activewear John Lewis is ranked 74 out of 75 in the category Bags and Luggage John Lewis is ranked 1564 out of 1578 in the category Clothes & Fashion John Lewis is ranked 1017 out of 1031 in the category Electronics John Lewis is ranked 231 out of 235 in the category Gifts John Lewis is ranked 2536 out of 2550 in the category Home & Garden John Lewis is ranked 204 out of 208 in the category Shoes John Lewis is ranked 586 out of 591 in the category Sport John Lewis is ranked 58 out of 58 in the category Toys & Games Looking at some of the reviews, they have serious issues with deliveries and order management. This actually accords with my own experience. I'd forgotten that when we ordered a dryer from them a couple of years ago, I sat around through their entire 7 hour delivery window, only for it not the arrive. I rang them and was told that traffic had delayed them and they've need to re-attempt the delivery another day. No phone call, no apology, nothing. I'm pretty annoyed about the current situation. Unfortunately, I'm drowning in work at the moment or I'd make a project out of turning the screws on them. On the plus side, they're clearly interested in solving the actual problem of the defective product.