Nickfromwales

The CT clamps usually have an arrow under the bottom of the clamp body, but these have sometimes been put in arse-backwards in the factory, so that’s the first place we look if such an issue exists. Your installer may be correct, that the clamps are installed as per the direction shown, but you need to reverse them to see if that rectifies any possible issue. You’d try reversing L1 for a trial run of say 24hrs, then put it back as installed and then go to L2, and so on. VERY important you don’t lose track of where they are atm and which direction they currently face; you can mark these with Tippex or such to help out.

Usually you can just about get a pound coin in between panels, so at nearly an inch it sounds like a big gap. In roof or on roof? You can space uniquely on rails but not with trays.

May just need counter battening as well as fundamental battens atop the sarking, to increase the air gap / flow.

I doubt there’s much point in attempting to make the 2 circuits independent, as the TRV’s will provide simple, effective control to each space with a radiator, whilst the system ticks over to the UFH in the background; so basically your entire heating system is ‘on or off’. The issue is, if you have a room stat downstairs there is a risk of that switching the heating off sporadically, starving the rads of flow and the sections of heat input. Theres a lot of info to be exchanged for us to fully grasp / offer a robust solution, but as above, get these guys back and make it their problem. The caveat is, they may be at max capability already, hence the crappy solution they left you with, so you may need to escalate this if they can’t step up to the plate.

The quickest route is to just add a TMV and pump to the UFH manifold, and raise the CH flow temp of the ASHP. I doubt you have enough wiggle room to just slow the UFH flow rates down, but it is a possibility; but then you’d need to dial the CH flow temp up by max 2-3° to see if the rads perk up a bit. This will be quite coarse, and as TRV’s operate the balance will shift as it’s all hydraulically interconnected; water flow will just go to the path of least resistance, so that’ll prob be the shortest UFH loop or the first rad that it ‘sees’. Ultimately, I think it’s time you called the installers back, sit them down, and lay all this out in front of them, as atm you’ve not got a system fit for purpose and a wedge missing from your bank account for the (dis)pleasure.

Thanks for the pics. So you have a single CH flow temp, and no differentiation between UFH requirements and those of the rads. Not a great setup afaic, so I’m not surprised it’s not ‘doing exactly as it says on the tin’.

That’s a glass half full moment, c’mon! Kudos to them taking ownership, and in the grand scheme this is a drop in the ocean, surely?

Most will go ‘bonkers’ to protect the system as their arses are in the sling if the system fails and the dilution is deemed to be the cause of the issue; if it’s investigated and found to have been too close to the wind / insufficient. Not so much of an issue if CE are supplying and installing and then servicing and maintaining it, but a different kettle in other circumstances I’d guess.

Ah. 6T to grade, but 3 already down. Yatzee!

New builds and conversions / change of use etc only atm afaik.

Ok then. Let’s stay up and fight this out! If there’s a duct, that means atmospheric conditions can / will exist there, plus ground moisture (damp); so you’ll have it from ‘both ends’ if you create a barrier with the foil. The condensation on the pipe comes from you / the house air, sweat from the ground would collect on the underside of the foil from the subterranean aspect. Just give me your bloody postcode and I’ll bring some pipe insulation and fit it for you, then it’s off to the pub for beer. You’re paying 🍻

Well if we can’t blame you, then you’ve just removed this evenings fun. Its a lot of work to hose the fines out of 3T!!

Then it’s you vs the rest of the world with that thinking. Oak = hardwood to every person I’ve ever bought it from, or fitted it for.

Airtightness and a quality MVHR system will be your biggest return on investment. Insulation plays second fiddle to these, as cold air infiltration (draughts) will promote ventilation heat loss vs fabric heat loss. Fabric one is relatively simple to top up if you get airtight and keep the place from becoming excessively cold in the first place.

Humid air is in the house. That hits the cold pipe and condenses. It’s coming from the depths of your house lol 😜. People breathing, washing machine, tumble drier, dishwasher etc. Please don’t go digging the floor up to look for the source, you’re the source.

I don’t think it is. The pipe just needs simple pipe insulation. Wrap the insulation with duct tape to stop the seam opening and that’s it. Simple!

There’s going to be movement, so I’d rather manage it and ensure it doesn’t then migrate further out, at a weak point in that complex bead. If you do as he says, and stop the render at the frame, then all you need is a decent “mastic man” to put the flexible seal at that point to allow the movement to happen behind it. Somethings gotta give, and you’re trying to remove the ‘give’.

Because the too will be warm, at room temp, and will pull the moisture up to it. It’s an odd thing (not really a phenomenon) but I saw this with a thermal (foil) underlay for laminate flooring, and it was sopping wet under it. The PIR idea is a bit OTT, and doesn’t wrap around and remove the air gap, unless you use foam to seal as well…. but messy and complicated.

They’re all single cell / partially closed, these ‘better’ ones, but are totally different animals to the foams from the sheds. Cheap stuff is like crumbly honeycomb when set, and you can scrape it out with your finger, but the 330 is insanely better and when cured goes a lot harder / stretchier, and has far fewer voids in it. Been using it for years on anything which needs airtight / cold / damp bridging to be resolved. Use it all around my windows when they were changed, and damp disappeared and hasn’t come back, much better.

I believe I have spoken……

Don’t make me come down there and squirt you with it. Just do as the Welsh fella says, and use that one. Now “go” 👉

Illbruck FM330 mate. Use that, and scoop the other stuff out.

Once the air gap is gone, the condensation won’t form. Does the pipe have some sort of duct, or is it straight out of the ground?

Water will definitely track / sit all along the threshold, which makes it even harder to discover exactly where it’s coming in. The extra silicone outside is probably adding to the problem, as the water cannot escape. You either stop the water getting in, or leave it a way for it to get out.

You just need to put some thin insulation on the pipework. That is the solution here. Covering with a foil patch will just cause it to ‘sweat’, and that’ll harbour damp forevermore. The hole in the floor needs to be open to the room, with just some rockwool stuffed down it, so it’s about 50mm below the tiles, to prevent draughts. If you can move the stopcock then do so, as replacing to would be a painful job after you build a kitchen over it. You can ask the plumber to fix a 90° bend at the point the blue pipe exits the floor, and then convert the blue pipe to 22mm copper and then go to a new 22x15mm stopcock in the unit, with all pipe under the slab insulated and forgotten about.