SimonD

I think you need to have a word with them. As you say, with 5kW which won't be running at that for much of the time (other than during dhw), the 28mm pipe is just too big. Tell them to sort themselves out and do it properly. There is the option to use compression reducers with those fittings and use 22mm pipe for the rest of it - there are some pieces of equipment that only come with 28mm compression but the manufacturers chuck in the reducers for 22mm situations in the box. But what do you mean by 28mm bends - not flexis surely as these units don't need flexis.

Ah, okay. How come you chose that over the newer r290 L series? Any particular technical reasons other than that the L series has to have an indoor unit?

Seems to have happened with Claude as I reached my new 5 hour limit somehow - even though the time was spent getting it to debug and unravel problems it caused in the first place! Infuriating. At least I was only locked out for a couple of hours until my next window opened up again. It feels like being back on the free plan. But sometimes I despair, causes lots of bugs but even worse, I gave it a page with CSS I had written and confirmed to work. Asked it to produce a separate CSS file using that and then strip out a load of duplicate CSS from other pages and to link to the new CSS page. It completed the task but over-wrote my CSS with its own CSS that didn't work and then forgot to strip out the CSS from several of the other pages. Sometimes I think it just loses the plot or else someone has got bored and decided to implement algorithm based enshitification for a laugh.

What exact Panasonic model are you installing?

Hehe, what you've described is room influence, although the best room influence simply sends an additional signal to the heat pump to reduce the flow temps essentially modifying the WC curve. But if you have control from the room, that's room influence as it calls to the heat pump - nothing to do with actuators/open loop in an of themselves. Room influence is just about adding additional system control which uses the room conditions as input. 😁

You don't need rubber feet on the Panasonics and you don't need to go to the expense of flexi connections to the heat pump either. You can buy and fit rubber feet if you want to and there is also a mounting frame available (with adjustable feet for uneven ground) if you need to install at greater height but this is usually only used for snow clearance. Yep, add another expansion vessel - shame it's not like the Viessmann boilers where there's a specified test procedure you can follow to determine if the built in vessel is sufficient, but it's quick and easy to add another.. Given your UFH installation, a full commissioning service to balance your UFH will likely take days to do properly given the lag in a slab and also is best done when it's cold out. Just buy yourself a few pipe thermostats and stock up on patience. Wow, I'm glad I was sitting down when I read this. @JohnMo has joined the dark side and gone room influence. I never thought I'd ever see the day given how adamant you used to be that it was akin to the devil 😉 What changed? Or is this another experiment?

I'm sure you've got to be on a proper wind up today, no?

Hmm, no. The logic defies me here. There is no possible means of producing a proper objective measure in comparison. Instead I'd hope that Rasmus et al would be making more sensible decisions around the necessity and means of travel and thus reducing it as far as possible, not trying to justify it on the basis of 'I do more for the environment so it's okay for me' which just gets us into more trouble and bickering. To affect change in behaviour there needs to be systemic change, because the system absolutely rewards air travel financially as a start right now - just think of the cost of a short flight from the SE to Scotland for example versus the equivalent cost of taking the train. The economics right right are shear insanity. But there are also other systemic factors that blind people to the environmental cost of activities and decision - so this becomes a societal aspect, but then there is of course the individual responsibility about taking a stand and making a statement, which in itself may affect the societal and systemic. But who is actually making this kind of stand in such a way as to shift the curve? Our politicians aren't, nor are other leaders, nor are celebrities really doing this to a great extent... but there are lots of more quiet people just getting on and doing it - maybe they're the ones that will eventually provide the gravity necessary to shift things from the bottom up? Who knows, but the winds are blowing in a direction that rather depresses me right now - it feels like taking a positive environmental stand is the higher risk path, both personally and professionally versus embracing and continuing with the status quo.

Oh, I've been there. Being stuck in that doom loop makes you want to chuck the machine out of the window. Claude, however, as been good to me today. Sensibly it's reminded me of design decisions I made a while back to pull me back from a minor tantrum I was having with a bug and database versus JSON. It's just pulled out a quote from the backlog to bring me back. Kept me on the straight and narrow. Thank goodness for a good backlog where I've asked it to log design decisions!

My son was telling me about all the flaws he's found using AI and I said that wasn't it great that AI has nothing like human flaws where we forget, overlook, turn up to work hung over and useless, sometimes just totally useless without an excuse, plain obstinate, and full of bullshit and with a tendency to hallucinate all manner of things, even without drugs. You could wonder who'd designed AI in the first place 😉 It's like that ubiquitous warning in all AI UIs telling us that it's AI generated and can get things wrong, so obviously unlike humans too. And surely the IT infrastructure definitely needs to be recreated....without doubt 😁 What's more worrying for me is how I'm now starting to recognise which AI has written the spammy sales emails I keep getting through from companies telling me how much they can transform my business with a few clicks of a mouse.

unvented maybe?

Yes, these are a good option. I always have a few in my fittings boxes as they can come in very handy.

Yes, you can hire the tools. But my honest opinion is that if you're just doing a room, you're better off using push-fit, or copper. I only use MLCP when I have a larger installation to do so if it's whole house, whole heating system, long primaries to a heat pump or something else significant, that's where it will make the difference, plus threading through a house is much easier with a PB push-fit pipe.

You have a heat only, or what some people call a conventional boiler. The biggest problem is the condensate pipe. It's not clear where it goes from 19mm pipe to the larger diameter, but as it's inside a garage and therefore subject to low temperatures, I would have fed the 19mm into a min 32mm pipe just below the boiler and then out to the drain pipe, insulated all the way. The other thing I notice is that the gas pipe is actually too close to the Consumer Unit - it should be a minimum of 150mm, but it seems like it's been that way for a very long time. The only thing remaining is to check the flue has been sealed correctly and is supported through the wall. I'm guessing they didn't touch anything else inside the house during the installation?

With pretty much all makes, it's very easy to go back to copper or plastic as they sell them everywhere. For example: https://naturalgreenheat.co.uk/product-category/wras-approved-press-fittings/transitions-mlcp-to-copper-pipe/ I've used Tweetop, Maincor, Riifo, Uni-Press, etc. etc. They are all pretty much the same. The only thing you need to be aware of is what press jaws the brand uses. Some are available that can accept both TH and U, some are only TH or U and some brands have their own. So when you invest in a set of jaws, just make sure you use the compatible fittings. I have both U and TH as I had one supplier who was very good with one brand and then seriously let me down one time by supplying a huge coil of 32mm that was damaged in transit because they couldn't be bothered to package it properly and made it a nightmare to return it, so I had to switch to something else with reliable supply. But for me it's useful to have both sets of jaws because I use the stuff on all my installs. With all the systems you have to plan out your job carefully to ensure access. Having a set of angled jaws helps but obviously adds to your setup costs significantly. The advantage with MLCP is you can often bend the pipe to give yourself access, but sometimes you need to use your imagination in tight spaces - e.g. crimp and then thread pipe into place.