joth

If you're reasonably competent / careful (i.e. keep fingers off connections) it's safe enough to do still powered up, but really no downside to shut it down first, esp if it's the first time you've poked about inside it. While open it'd be worth tracing each of the cables back to unambiguously identify which pump/valve is connected where. You only need to remove 2 screws, on the bottom edge of the front face.

To clarify, are you self building as owner occupier, or building this as a developer or as a build to let? If this is a business venture, I certainly appreciate why you would be biased towards minimum capital cost, least skill and least risk of call back to maintain/repair. But most of us here are owner-occupiers are naturally more interested in long term running cost savings, which can only mean using a heat pump if using electrical heat source. You consider 100m2 to be such a small house, yet it's at the upper end of the UK average size (estimate of 85-100m2). ASHP + wet UFH or rads is pretty much de facto option for new builds now, so the size is not a issue. And of the two UFH is lower maintenance than rads over the lifetime of the house, that's for sure.

Control4 light switches would normally be over knx which was one of the options I mentioned, so (a) it's a bus so not that much extra wiring, maybe even less, and (b) if control4 goes bust/obsolete you can swap stuff out for equivalent from one of the other X hundred other knx vendors. But yes this conversation is only relevant for anyone already set on using in wired digital controls. Shelly is fantastic for the odd fix to get out of a tight spot, but god forbid I'd personally never design a whole house dependant on it for every fitting. Especially when you add motion sensors and door contacts to the mix.

Your ecodan is driven by an FTC6 controller, white metal boxy thing. If you're comfortable taking the cover off that and getting some photos of the innards it should be possible to diagnose if the valves have been connected up incorrectly. The FTC has 2 complimentary outputs for dhw / heating switch over. In S plan with two normally closed valves you should see one wired into each of those outputs They're labelled OUT4 and OUT13 on the PCB because why have one numbering scheme when you can have two?

Indeed they didn't, my question was directed to @SteamyTea specifically responding to his comment "if you are installing, via MCS, you can only fit the modules that have been certified (the 4 on the list)"

OK maybe stupid question, but why does this only impact installs via MCS? Building regs are building regs and need to be complied with, regardless of whether going an MCS route on the installation. In that respect I don't see this so much as buck passing by MCS, as MCS not wanting to have buck passed onto them for something that already has plenty of others taking some responsibility for.

No. I'm not aware of any light switch using wired ethernet. But yes CAT6a to each light switch is a possible option if doing something like knx, Loxone tree or retractive switches. Many variables so there's no one size fits all answer. (No hiding the fact it's considerably more work to plan than conventional wiring)

What stage is your build at? I'd always advise putting in cabling at 1st fix to support proper (fully local, wired) control rather than finish the build then immediately retrofit wireless. Even if you can eliminate the Somebody Else's Computer aspect of consumer smart home gear, the reliability of wireless connections is generally terrible. Velux one of my least favourite vendors rn. But they all suck over the long run.

FWIW it looks there's a few places stocking these THB23031 auto-calibrating models now, e.g. https://www.ecowizard.co.uk/actuators/salus-thb23031-auto-balancing-actuator/ https://www.plumbarena.co.uk/product/salus-thb23031-ultra-auto-balancing-actuator/

ON a recent install we intentionally turned up the EPS switch over time to several seconds. Computer kit inc PoE switch is already on a UPS anyway, and this way most manually operated appliances in the house (microwave, ovens, dishwasher, projector etc) will have a clear 10sec power loss and won't reset/resume when powered back on. this was the whole house can switch to EPS but actually come back up with a relatively low power demand The other cunning idea was redundant powering Loxone miniserver from both its own dedicated 24V PSU and the UPS backed PoE feed. This gives protection against PSU failure as well as power cuts, and cost order of magnitude less than the Loxone PS+B (given the UPS was being installed regardless)

Remember this is best-case COP and A2W (thanks to MCS) generally quote SCOP not COP

Ideally a TIA CAT6a certification test (while drawing full load on the electrical equipment sharing that trunking, which if PV might mean doing it on a sunny day lol) But if this wasn't in the original contract I can see them at most giving you a basic cable verification (buzz) test https://www.fullcontrolnetworks.co.uk/questions/copper-cable-tester-your-options/

Late reply, but that trunking is not ideal for CAT6a cable feeding the whole house, as a) there's not going to be much space in it if you have 96 cables as some here suggesting LOL. (Or even 50 cables) b) it's generally not considered best practice to run data and mains together in parallel Not strictly a regs violation and CAT6a should be shielded to minimize interference issues so you may be fine, but if anyone designing from scratch I'd recommend splitting mains and data to separate trunking

What is the heat source? Gas combi, oil, ASHP? What are the floor finishes? End of day if you don't care about increased running costs go ahead and install it per contractor's recommendations. It'll take many years of reduced bills for the huge cost of dig out and reinsulate to pay back. Using minimal floor finish like amtico will promote as much energy as possible to come up into the room, and is less prone to damage from the higher flow temperature you'll need to run. But keeping with radiators will be much cheaper to run.

Yes, I made this mistake too - thought 4x2m would be plenty for plant+washing/util+cat feeding but it's way too small. Having 2 doors into there (access through to garage) doesn't help. Also I think I'd push a bit harder to get the laundry in the upstairs fam bathroom (or adjoining it). In addition, I regret going with plasterboard and 25mm service void in the plant/util room. It would have been much better with ply-lined walls, no service void, and have all services in surface trunking. I've tinkered with so much of the ASHP since install (3 years ago) this would all be much more robust without crumbling plasterboard. Finally, putting more effort into coordinating the layout of manifold/UVC/ashp pumps etc - The installers put the all in rather haphazardly again not making best use of the space. Other than that, the main thing I'd do differently next time is demolish and rebuild rather than deep renovate, perhaps doing something more ambitious with planning like upside down house, if the plot suited it. (Our current house really would work nicely like that, enclosed bedrooms on GF and nice views across road to the common on the FF). This is not so much a regret of the last project: on balance I'm far happier we cracked on when we did rather than drag out a couple more years on the design and PP for a rebuild, but if doing it again, a clean sheet rebuild would be the main motivator.

Hmmm well 10 weeks running it with the flow sensor disabled it seems to be performing just fine, so I'm still inclined to think it's a sensor failure. Ideally I'd borrow a replacement to test - they're not cheap, and a bit of a pain to get hold of. I only really need it to get more accurate energy delivery estimates from the controller.

Welcome! Another Hertfordshire based self-builder here. I did a deep retrofit in Harpenden in the pandemic, and been helping with M&E and home controls for a number of friends on self builds since then - happy to have a chat on local options for this if you're nearby, feel free to DM me. If I am reading this correctly, from the elevations this is a 3 story build but includes plans for 4 floors - It looks like the first and third floor plans in the series are alternative options for the "middle" bedroom floor: one with w cavernous placeholder "storage util" room, and the other with it built out as a cinema and safe room. So in fact it's a slightly more modest 4-5 bed house?

I'm using a Carlo Gavazzi SSR with phase angle switching (0-10v comtrol) driven by Loxone. Runs cool and no issues so far 4 years in. I see they even do versions with modbusTCP control which would be even easier integration to home assistant

My experience for passivhaus (N=4 now) is 1/ never plan for "no heating" - seen this in one, the regret (and cost and disruption) of not laying UFH pipes is real. (I advised they should but by the time I was formally employed, the floor was already poured) 2/ a building wide model (e.g. PHPP) is just fine for heating - so long as the heat emitters are sensibly distributed through the area 3/ room by room is more necessary for cooling requirements than heating requirements - especially bedrooms

Wet UFH everytime Worst case is you don't need it, but it's relatively cheap to install the pipes anyway during build vs virtually impossible to add them when you find out you should have done later. This logic holds regardless of sap, phpp etc.

>To be honest what mostly let's us down is the gym/garage door That's not so surprising then, although what is more surprising is that the garage was included inside the thermal envelope at all, at design stage. As a garage you certainly wouldn't and even as a gym, I wouldn't expect it needs to be at the same temperature as the rest of the house. Can a more airtight boundary be made between garage and house - especially around any connector door? While it may not make difference to the bottom line airtightness figure, it may make a big difference for heating efficiency in practice. The thing about needing to know to do 2 tests is something every architect / builder / TF supplier / MVHR supplier _should_ know and convey to you. It's just a shame very few would. But to add to others already did say - very impressive build and such a strong attitude you both carried through it. Not easy to come through it unscathed - I know!

This isn't compliant with part L though is it. That requires at least 2 zones (and recommends one per room, which will be where the OP's installer is getting that from)

Yes, as 2 zones, the ecodan FTC6 controller manages all this, you can set each to a different flow temp and (with the correct electric mixing valve) it will temper down zone 2 e.g. for UFH. Although if it didn't, I have Loxone home control system and that can manage a mixing valve too, to make effectively unlimited zones of different temperatures. (I'm using Loxone to calculate the flow temps using weather + load compensation, and it pushes them to the ecodan FTC over modbus)

Note the wires don't need stripping before inserting as the crimps include simple insulation displacement. So you just need enough flex to strip off an inch of the outer jacket But my suggestion is also partially tongue in cheek, it's the cheap and quick potentially weatherproof fix (the gel is like vaseline in keeping water out) but clearly a bodge. Almost most of the BT copper wore telephone system runs on them...

https://www.google.com/search?q=Gel+crimps not the toughest google... I normally get the tlc ones https://www.tlc-direct.co.uk/Products/GPJC2C.html you'll need 8. you maybe able to find a little waterproof junction box for the lot