-rick-

If the regs say something along the lines of appropriate RCD protection needs to be installed. Then you need to choose the appropriate RCD. RCDs come in many flavours and the issue here is that Valliant heatpumps put out waveforms of a higher frequency than standard RCDs can protect against. If they installed filtering in that heatpump to eliminate the higher frequencies then such RCDs would not be required. That the manufacturer recommends something is a consequence of them helping installers meet the regs for their device as currently designed.

This doesn't really match what I've seen before (though again it's been a while). I suspect this is a case where they are thinking aircon not cooling and designing for the 'cool a hot room down rapidly' type situation with all its other complications.

I think the RCD is to protect the cable so inside the heatpump doesn't necessarily work. You do make an argument that the manufacturers should install better filtering inside the unit so the noisy signals that need complex RCDs don't leave the unit. That would impact efficiency though I'd guess.

Ah, trying to make something that wasn't designed for it do cooling. I thought we were talking about things that did support it but the manufacturer didn't recommend.

Not Valliants fault the electrical standards were clarified that these things were required.

That sounds like you are thinking of switching from an insulated slab to a non-insulated one. Thats a different decision to just changing how you finish the floor. You'd need to get the drawings all adjusted as your levels will be out and it might affect the heat loss calculations + SAP too depending what you are doing. You can just top the insulated slab with a leveller and a normal floor finish if you just can't get the powerfloating done. That would save a lot of the rework of drawings etc, though you might need some depending how much height you are adding.

That looks fun to move

Not sure I understand why they said any of this. It's been a while since I looked but when I was looking I'm pretty sure I saw plenty of examples of shallow depth (1m) coils being set up for heating and cooling without a problem (I was tending to look at other countries as not so much used here). The problem with them is sometimes you need a lot of space/length to stop them freezing in winter, not a problem to dissapate excess heat in summer. DHW cylinder to dump excess heat sounds like they've gone way off topic. Sorry, I feel I'm missing something here. If you use a GS heat pump to cool a property the heatpump is actively heating the ground during this time. The problems with ground source I thought were more with the ground freezing when you try to pull too much heat from it during winter. Didn't think adding heat to the ground during summer was a big issue comparitively. This was my understanding and it's commonly used and supported in other countries. Though I'm sure I've also seen plenty use the heatpump for greater effect. As at least in some ground conditions it helps recharge the ground for the winter heat demand.

Oh I get that. My assumption in making the point (and assumptions are always dangerous) is that the funding would be available in a way similar to heat pump grants, where you choose the contractor and agree a spec before moving forward. In that case, with Rogers knowledge it would seem possible to seek out a reasonable contractor, not the worst, and make sure the spec is reasonably close to the end goal and be able to monitor the work. If the schemes are more in the form of sign up to it and basically hand over all control and decisions to a 3rd party and the end result it whatever they decide with you having no influence then it's a completely different situation.

*deleted I'm talking about something different from this thread*

I think the issue is with the mixing valve. A normal analog thermostatic valve can't have different set points for hot and cold. I'd guess that many digital ones also require more setup work/software support to do this. Maybe their inbuilt control of digital valves is the problem? If so, wouldn't seem hard to make sure you bought valves that could handle two set points and wire them seperately from the rest of the system. Not sure off hand why they would need to be wired into the heatpump except for monitoring reasons, they should be set and forget.

Definitely sounds like it should be possible. They are relying on mixing valves and running the heatpump at the highest (heating) or lowest (cooling) temperature so it's not necessarily the most efficient but I wouldn't expect you to need the very low cooling temps outside of heatwaves.

You've complained before about how the building regs make it difficult to do smaller improvements because if you start then you feel you would be forced to spend a lot more to bring everything up to spec. (Though from what I've read here it sounds likely that this is a worst case fear rather than what is likely to happen in practice if you actually consult with building control). You've also complained about not being able to get a government funded upgrade to your electricity and this combined with the insulation improvements issue is why you don't feel you have the option of moving away from oil heating. If you can get such a large amount from the government to make improvements to your house (improvements that almost certainly would deal with the building control issue) even if the work has issues, couldn't you use it as a starting point to then make your own improvements (that you would like to) along with fixing up any issues you saw with the install? This would likely then open up the possibility of electric heating options for the future if you decided to go that way. Reckon you'd still save an awful lot even if there were some issues that for expediency you decided to fix yourself and it sounds like you have the skills to closely watch the installers and pick up any issues to have them fix the majority of them before they left site.

No specific knowledge here but I am curious: 1. What is your current plan? 2. They claim to support dual zone heating with different temps? I'd assume so. How are they doing that? 3. Are you referring to purely simultaneous cooling? Can it do one zone at a time at different temps? I have a couple of ideas for things you could do but depends on the proposed setup.

Looks very much like you have a manifold like this: https://ambienteufh.co.uk/product/stainless-steel-underfloor-heating-manifold/ The ports on the far right are fill/drain valves I think.

Sounds like maybe a step back is in order. If you want to export you need DNO approval. AFAIK if you don't want to export you can get inverters and set them to not export and not worry about the DNO. eFIXX interviewed someone who got e.On to approve a non-MCS install for export too (though the whole install was don't by a qualified electrician).

Isn't that the majority of houses that have a cavity? I thought the bulk of houses built with cavities without insulation had now been filled. Obviously there have been a variety of techniques used and problems identified with some but it's been step three of improving insulation in houses since the 80's. 1 and 2 being loft insulation and double glazing.

If you have the space AFAIK there are services you can sign up for that basically put you on a list and when a tree surgeon has a load they want to get rid of near you they will know to call and ask if you want it. Zero cost because they usually have to pay to dispose so its a benefit for them. Though obviously you need enough room to take a decent sized load of chippings.

Did you find any issues? Assume it's been working fine since the incident?

I think it's a fairly common option (in other countries) to use a compost pile to heat greenhouse during winter. Heating a house is a whole other level, maybe if you have a small farm.

Looks good. Congrats! Beer time!

But if you are paying the original installer to do it vs DIY then the benefits might not stack up. Can't imagine an installer would get out of bed for a job thats not costing £1k,

I'd hope the grid aren't designing around this. They have to design for the hottest day of the year being the longest for sun anyway. On any modern solar install where roof space allowed, the inverter on days like that will max out before peak sun is reached as there will be a certain amount of pv overprovision. So adding more panels won't significantly increase load to the grid at the most critical time. Yes it might stretch the load out over a longer time but the difference should be marginal. The benefit of more panels is to generate more in cooler/less sunny conditions where overheating won't be a problem (if the grid can cope with peak inverter load as it should be able to anyway).

I think you need to worry about notificatoin if you are on FIT. Non-FIT I dont think it matters unless you change the inverter. Adding extra panels to an existing inverter needs careful thought though especially if they are in a different orientation. If you have a spare MPPT then its easy, if not then needs careful thought.

Are you looking at the manufacturers site? https://www.edilteco.com/en/catalog/thermal/eps-beads-coated-by-e-i-a-additive-politerm-r-blu/politerm-r-blu Not sure that's the exact product, just the last page I was looking at, following through from the site Nick linked.