joth

interesting point. I've always been put off playing with this on the basis the schedule is entirely driven from the cloud so an outage will leave it in an odd state. (And, it's in competition with the FTC6 built in schedule function and the schedule in my HA). you're right though this is the easiest way to set variable flow temp. (The other would be to abuse the zone 1 vs zone 2 settings, have them both plumbed to a single set of emitters but switch between which one calls for heat based on time of day. No good for me though as I need the dual zones for its intended purpose, as i have different zones for UFH vs FCU) Thanks again for this @Gary68. I had another go with it, and actually got something working very nicely (in terms of performance in practice, most definitely not for elegance of design). 1/ Loxone uses dry contact inputs to control call for space heating (UFH and FCU zones based on room stats and house occupancy), and also sets the "Smart grid - On recommendation" inputs to FTC (based on excess PV generation, or octopus Go cheap rate) 2/ The ecodan FTC local controller has a schedule to disable DHW reheat at certain times of day (basically for evening CO2 peak, and after bedtime up until the overnight cheap-rate starts). 3/ The MELCloud app has a schedule setup to flip UFH into Target Flow temp mode (t=40degC) during cheap rate, and back to Weather comp mode at the end of cheap rate. Bonus: I have created seasonal schedule, so it can finally automatically enable cooling mode from May to Oct, no longer needing the twice annual mode flip. It's sad but I need all three control systems, as each is doing something that can only be done via one of those interfaces, pretty much as listed above. Other challenges I had to overcome - the actual flow temps can't be set in the MELcloud schedule, so you just have to hope that what was last set manually still takes effect when the schedule turns to that mode - the local controller does not support automatic day light saving (no NTP support is very sad for a wifi connected device in 2024). I always forget to manually set it to BST, which messes up the DHW cycle. So as a workaround I leave it always in GMT, I have set the controller cooling/heating seasons to match DST as best I can (basically March to Nov) and I do the mental arithmetic to configure the "summer" schedule to correct it for DST. Going to stick a big reminder label to the unit about this, as I will always forget this! - the MELcloud app crashes if you try and enable seasonal schedule. I debugged the javascript and manually crashed over the problem line (spoiler: they misspelt "noXss" as "noxss" in a dictionary lookup) so managed to enable this feature. I attempted to report to mitsubishi but their web feedback form also crashed on me, LOL. If anyone needs pointers I can try and write up the steps a bit more. - our bamboo flooring does not like to go up to 40degC, so I have Loxone monitor slab temp in those rooms and close off the corresponding manifold actuator when it exceeds 26C. The majority of the GF is porcelain so this emits well during this cheap rate boost period. Last night was cold enough to need heating on, but not cold enough to hit defrost cycle, and it's the smoothest blast of continuous cheap rate lecy I've managed to eek out of the thing, with no cycling: over 2kW sustained through the whole period up until DHW reheat cuts in at 3.30am. (In weather comp mode it only draws about 0.5kW even when it's subzero outside; great for maximizing COP but not so good for getting max value out of the overnight cheap rate) Here you see the bamboo flooring modulating very nicely at 26C, while porcelain floor is still ramping up temp throughout the boost heating period:

Indeed - like all energy saving measures, doing it yourself would seem to be the "luxury" option so gets full VAT.

Just a note that A2A already has a small subsidy in the form of zero-rated VAT on supply&install

So gain load compensation at the loss of weather compensation? Or do OpenTherm stats support both? Homely is the other option . be interested to here some real world reviews of it https://midsummerwholesale.co.uk/buy/homely/homely-smart-controller-V3 (No ecodan support yet, else I'd already have got one)

Just to clarify, the MVHR is in the main building, not the outbuilding? If so, yes these are two completely independent projects so by large it's just confusing to wrap them up in a single question. (aside from financing constraints, but you don't mention that at all). For the Solar, as you say main limit is getting the supply cable in from the meter head. Dig the trench with duct for this when you're doing other ground works, for the extension founds maybe? Is the outbuilding already there? If it's having a new roof, then do the solar as part of that project, going integrated panels should save on roofing tiles. You may be better running DC cable to the meter head and placing the inverter there. Depends if you may want to add batteries (dc coupled hybrid inverter) and where you have space for that. MVHR main thing is to get it in before making good work is done. The duct work can always be installed incrementally rather than in one big hit. Just be sure to keep ends of pipes sealed to stop dust etc getting into them during the works. Presumably you're aiming to improve airtightness around the existing property, and achieve a good level on the new extension? To get best benefit or the MVHR people generally cite <3ACH as a goal.

up to the sparky... So far 0/3 used any conduits.

There's a very real difference though. Non polluting options exist for heating a home, so it's hard for a clear thinking person to accept a greenwash polluting alternative. Aviation is much tougher. Every current and credible future technology will create some degree of pollution, and it's unrealistic to enact a global ban on all air travel, so we're left looking for the least worst option. Obviously it's very easy for those that never fly to insist no one should, but honestly good luck to you in finding a political party you can vote for that will be successful turning that soap boxing into action.

Btw this wiring does limit your choice of motor. Some require permanent power and 3 core of "dry contact" relay switching, so they would need T+E and a 3 (or more) core control cable. I now specify 3+E and cat6 to each motor where the model isn't yet selected. OTT but it's the most flexible option

I think it's mostly down to whoever is signing off your install for part P and what they're happy with. I've worked with 3 sparkles on installs now, none of them wanted local isolators for switched mains feeds to blinds/curtains/windows but they do want isolators for any permanently powered fused spur. One was happy for the isolation switches all to be grouped together in one cupboard per floor, another wanted then in the closest "obvious" place. Interestingly they all want local isolator for electric underfloor heating even if it's remotely switched and even though the odds of needing to do running maintenance on a heating element glued under tiles seems way lower than a motor and blind with strings and stuff that may get tangled up day to day. But there you go, I've given up trying to guess and just ask them what they want

I terminated the cat6 in a trailing rj45 plug that goes right in the back of the usb adapter, which in turn is cable tied beneath the vanity unit. The goal is usb power so hiding the adapter away wherever possible seemed to make sense. A standard A to C adapter would work, although PoE to usb C is certainly available as the Unifi doorbell pro requires such an adapter. I can dig out links if needed. Edit here https://www.broadbandbuyer.com/products/48002-ubiquiti-uacc-adapter-poe-usbc/

Yes, but you'd have 2 jumpers in each block, one incoming from the prior block, one out going to the next. I used this scheme when I have random CAt6 each with slightly different things going on (often for outside and out buildings, or heating controls etc). When I have >8 CAT6 with a consistent assignment then using interconnected blocks comes into its own. (E.g. for light switches and room sensors, each room being another line)

A lot of people mix up efficiency and speed, especially when it comes to heating. It's like saying a Ferrari must be more efficient as it gets you there sooner. Being very generous, you could read it as time efficient. Like, an electric fan heater is very time efficient way to warm up a room; you waste less time waiting for it. But a heatpump will cost less doing it Notwithstanding that, totally agree different metals is complete BS. The one caveat is a badly furred up rad would be less time and money efficient: it is effectively internally insulated so the full heat never really gets out of it so over extended period you waste a lot more heat on the circulation pipework (especially if it goes through cold zones) vs the small amount actually usefully delivered to the room

They look worryingly like UK boxes in round rather than the characteristic EU look, I'd worry about the screw hole centers being wrong. Try https://knxshoponline.co.uk/e135-o60mm-extra-shallow-only-35mm-deep/ They have a pretty good range to chose from

Correct. The non interconnected block actually have 4 interconnected terminals per signal, 2 facing down and 2 facing up. In most cases you use just 2 of them, the spares are mostly useful if daisy chaining a signal (like Rob does with Tree and power lines. Which mostly comes down to personal preference, if you have the space for it )

LOL cross post. Blue and Browns are in non-interconnected blocks to need a dedicated connection per core. Orange and Green are all fully interconnected (in my colour scheme) hence fine to use the full pair of connections per block level.

So here's a close up of the one I posted earlier: 13 CAT6A cables, the green pairs are all smooshed up in the top side, you can see two cores going into each block level. but I spread the oranges out over top and bottom sides, just to make it easier to incrementally power things up and debug during commissioning. As you see the power and tree feeds just nip in the very bottom L8 of the block. The browns and blues are arrayed either side in non-interconnected blocks. (I used the blue ones as I didn't know the trick from Dan when I ordered). These have sparse connection on the bottom (cabinet facing) side as not all cores are used on all runs. (I typically use brown for the first device on a run, then Br/W if it has 2 retractive devices, and so on: then Blue, and then Bl/W for a fully loaded run, hence why columns 4 and 14 are fully loaded but subsequent blocks less so). HTH

I'm just concerned that they won't fit in my cabinet! according to this data sheet they're quite big. I might stick with the 8-way terminal blocks even though it'll end up more expensive. No, you misunderstand what I'm saying. The 8 level blocks have 32 connections - 8 pairs on each pitch (up / down facing) The 16 level blocks you link have 64 connections each! Keep with the 8 level blocks, but you can cram >16 cores into each if you must.

Yes. My "neater" scheme relied on one CAT6A per room rather than per device, so was about 15 cables not 32 for me. Also I needed all cores connected anyway as the brown and blue pairs were on retractive switches into DIs Using interconnected and ignoring unused pairs is fine, especially if you leave a bit more space around the terminals to manage them all. Not each interconnected block actually had 32 spring terms! As they're paired and there's 8 pairs on top pitch and 8 more on the bottom pitch. Personally I'd use the 16 topside terms max for the outgoing cables, but that's still just 8 blocks needed for all your power and tree on these cables. Note the last photo I shared was actually hybrid: interconnected blocks for orange and green, and separated blocks for brown and blue. Slightly tricky, but the sweet spot for density ime 2 layer are 2 layer plus earth. So each T+E needs a 2 layer, each 3+E cable needs a 3 layer block (as a good approximation). For 5 core I normally use 2x 2 layer. Yes. Assuming you have switched live then use busbars to common across all the neutrals. LED strips (if on T+E cable) tend to have common +24V and dimming on the negative leg (so called common cathode) so these you busbar the +24V positive side instead.

Do they physically have pipework to connect an external source into? If they do, what is the point?? If not, then it was never going to work. Are you reading an online manual, that they've modified since you purchased, to disadvise something that was previously advertised as supported?

Which would be more complex, lower COP and probably more labour cost than just doing the conventional install with an R290 unit. If the pcm needs 50° then it may work even with the ecodan (55 max output) but I'd go with the valiant even if you run it at 60 you'll know you have headroom for the lifetime of the components. It's cop should be pretty reasonable at 60

If you get an R290 ASHP like Vaillant aroTHERM it will do 75C output and be usable with the SunAmp. It's a bigger project then of course, but will slightly reduce your DHW costs. But if expediency is the goal, DIY looking increasingly favourable

This makes you ineligible for BUS https://www.ofgem.gov.uk/sites/default/files/2023-09/BUS PO guidance V2.3.pdf (my emphsis) "4.25. The heat pump or biomass boiler must provide both space and hot water heating and be capable of meeting the full space heating and hot water heating demands of the property." What is DHW currently supplied by? (aside - it appears upgrading Willis to ASHP is covered by BUS, so you can claim it on this basis regardless of being a self build vs any other new build. "4.23. The new low carbon heating system will need to completely replace an existing fossil fuel heating system or electric heating system which does not include a heat pump.")

As you want this done asap, the possibility of using BUS comes down to whether you can find an installer ready to move at a speed acceptable to you. There's no doubt you could get it done entirely within the BUS grant if time wasn't a pressure, as yours should be a very simple install, no emitter or UVC changes needed whatsoever. So you could chose to put the excess money a DIY install would cost towards covering your excessive Willis bill this winter and hold tight until an installer gets to you. Depending where you are there maybe small installers available or have to rely on octopus and even BG now... One other thought, are you eligible for BUS? There's no boiler being upgraded, and your self build is complete (?). Check the wording

Personally I'd rather the noisy stuff be outside my house than in it I think the planners either don't care , or care about the visual aesthetic as much as the noise It's neighbours that care most about the noise, and as most are installed under PD the planners don't actually get a look in on it.

ASHP used for DHW and for heating? DHW will be a fairly consistent load and could well be this. Space heating will obviously vary according to the weather. Also do you have an immersion heater on the ASHP? Maybe try isolating it. At very least I'd power the entire ashp off one night and check