Nickfromwales

You set the setback temp ( actually it’s referred to as nighttime / unoccupied “economy” temp ( aka ‘off’ ) and daytime “comfort” temp ( aka ‘on’ ) ) to the lowest temp you can accept the house falling to at night. youd probably be best setting it to 16oC and most of the year it’ll likely not come on much anyway. The generic ‘economical’ advice you got is just knee-jerk I-can’t-be-bothered-to-go-into-detail reply. Pretty much the norm.

Masking tape is you friend. Don’t leave it on, it must be removed immediately after tooling / finishing / dressing the silicone. A cup of water and baby wipes are essentials, and always wet your finger before attempting to smooth. Smooth the excess over onto the masking, and peel away when happy. Once peeled the silicone edges will fray slightky, so one more wet finger or wetted tool run should finish the job nicely. Maybe a practice run on some scrap first would be best to get you ‘fully trsined’

That’s a very coarse way to introduce UFH. As you’ll have a lot of concrete to heat up and keep at temp I expect that the flow temp would therefore need to be considerably higher than if the pipes were in the slab itself. Thermally isolating the pipes from an existing ( therefore possibly insulation unknown / not present ) slab is paramount. The overfloor systems deal with this in a far better way imo, and I’d only consider the ‘cut groove and lay’ system in a thin slab with known insulation, if I could self level ( therefore fully encapsulating the pipe for optimised heat transfer to the surrounding material ) and if I could tile or lay a decent thickness engineered floor to absorb and diffuse the heat as effectively as possible.

My point was if you purposefully intend to rent an annex, b&b or holiday let etc, then you would ( iirc ) need to do a ‘district’ heating system that supplies the buildings with heat and hot water. One system that is eligible for ND not a few individual systems gauged on their own circumstances / merit.

Yup. Grab the vat, then convert. Without commercial gain you don’t get the commercial ( called non-domestic ) RHI, which is a lower rate but 20 years vs 7 for higher rate domestic.

Just if any shower door seals etc. Just a generic 'heads up' to other readers if not applicable to yours

One option; The over floor / over lay systems

Go all out and start afresh Get a silicone removal tool, score the silicone first with a Stanley knife to get things moving, ( don't scratch the tiles ), and then get a silicone remover such as CT1 multisolve / other. A few applications will see the old silicone dissolve and go to mush, and with repeated applications the old shit will all be off and you'll have a blank canvass. Labour of love though im afraid. Start up high so the product works as it descends, and don't let it sit on any rubber seals ( mask off if unavoidable ).

We would expect nothing else All depends if there's just gaps to fill back in, and the original stuff is in good repair TBH. Main thing is that it is DRY, as silicone will not take to anything wet. Best to dry it by blasting it with a hair drier for a good 5-10 mins, and then leave to cool right off. Dry the majority with kitchen roll first.

Modern gas hobs will have an FFD ( flame failure device ) so the gas shuts off without the presence of a flame Idiot proof.

self propelled

The duff link was to one in a toothpaste tube Been a long day. This is the correct link...….."Joys of modern technology", my hairy welsh arse it is!!

bugger ill change it in a mo. 2nd one is the winner

@lizzie Would this help? Link Stop the press ( quite literally ) I thought id seen these. Back of the net

What alternative would you have? Radiators? Don't discount a hybrid ASHP fortified with LPG. You can then also fit a gas hob / gas inset fire if easier / meagre electricity supply.

Would any of the units be rental ?

Don’t fit an instant, such as a Steibel as you’ll regret it. Incrementally something like this is far more bang for the buck. If you see a higher demand in the not too distant future then for a handful of tenners more you can go to his bigger brother. If you do a bit of storage you can heat on economy perhaps, rather than peak on demand consumption. Case dependant of course.

I'd deffo go for a 22mm 'backbone' and drop to 15mm when you et to the last 2-3 outlets. What hot water device are you fitting? UVC?

Will do. I'll be speaking to the installers ( I've subbed in ) later this week for a progress / scheduling report so will get some info asap. Its the Eco Angus Arligno 200 I went with, 40kW ( for the thicker walled steel ) and a much bigger fuel chamber for a lesser number of batch burns per TS recharge. £12k back over 7 years isn't to be sniffed at !

@iSelfBuild We'll have to change your username to Sarah Beeny at this rate !

@jamiehamy Sounds like a cracking idea to me. I've suggested this to a number of clients now We did another on a log gasification boiler instead of a WBS+BB as the latter didn't attract RHI, but the LGB does. Lots of great 'commercial' incentives about, but not many people jump to take advantage for whatever reason I suspect its because of the fear of the capital outlay, but there are loans about specifically to facilitate this IIRC.

25mm is a decent sized main for a domestic dwelling. You may be having extra bathrooms, but you'll likely not use them all simultaneously. If you think you will use them / have very high DHW demand then I doubt fitting a 32mm main to the existing mains ( street ) supply will make any notable difference TBH.

Just buy some cheap pipe insulation and lag the pipes where the timber is the only support. The pipe then moves within the insulation and it cannot degrade then.

Passive house ( aka well insulated build ). Sorry, a bit late and I'm cream krackered.

Just for your sanity, popping a soil pipe through a PH wall will not bring the 4 horseman knocking