Nickfromwales

Yes, that would be a healthy benchmark for sure. Also, the figures usually do not allow for maxed out self-consumption either, so the projected economics can be improved upon by something as simple as a PV diversion controller to DHW. Adding an EV charger of the same family / software base ( eg so they ‘talk’ to each other ) would allow pretty much 100% self-consumption, if the EV is routinely tethered during the hours of sunlight of course. Cases change for retired / working full time / working from home etc so no 2 scenarios are really the same.

Same as last and current then, as these were / are woodcrete. Cementitious parge which was left to dry, then PP applied to all the joints after it had had a couple of weeks to shrink back and dry. Hairline cracks appeared on just about every joint / mortar line, so, parge alone will get you so-so but parge plus PP will get you as good as it gets. AT test of 0.88 on current one which was not expected. Tres bien. Only let down by the doors and Windows tbh as I recon the fabric of the build would have scored sub 0.6 if tested independently. Use SBR on the perimeter of the slab and then seal the walls to the floors also if you want to go for belt ‘n 3 braces. (Styrene Butadiene Rubber (SBR), is a water resistant bonding and sealing agent, and shares many similar characteristics with PVA. One key difference is that, whereas PVA remains water soluble after drying, once dry SBR is not. Ed)

Yup. Plus a reasonable amount of diligence with a site survey before submitting figures. Just about every single proposal we’ve ( collectively ) put forward for my projects have either met or exceeded expectations. It shows the software allows a bit of ‘real world’ accountancy.

What is the substrate? Woodcrete / masonry?

Yup. And all the current nay-sayers moaning about the lack of returns on the PV installs will all be crawling over broken glass to fit some then. Prob is, then the PV will have gone up too. We've just quoted 9kWp at £11.6k ( before VAT ) with a breakeven point in year 6.5!! 80% performance warranty ( guaranteed ) for 25 years. Irrefutable sense, and PV is your best defence against rising electricity prices. Hoping to get time to do mine this year.......fingers crossed. Sun will keep rising, so will fuel costs.

@Bitpipe for one, used a stand alone basement contractor and then built a timber frame atop ( MBC Timberframe ). They're in Gloucestershire iirc. Options are available for 'mix n match'

You use tapes and membranes strategically, alongside the parge coats etc. How good a job you do on the parge will reduce the amount of membrane / tape you consume, so use that to do the major gap filling alongside a quality closed cell air control foam ( Link ) for a complete solution which will last a very long time. We've had great results with Passive Purple, a spray on or brush applied ( 2 different types ) liquid airtight membrane, which we've recently applied over both parged and non-parged woodcrete ICF structures. Very happy to recommend Adam White ( supplier of the PP product link ) whom I have spoken with at length for solutions to attain airtightness in my 2 most recent ( clients ) projects. He was very helpful indeed, and gave us great support for the correct selection, application and integration of the product, vs differing substrate types. He was also very well versed with the world of "passive house". With a recent very challenging Velox build he came out to site to go through everything wit me in person, without any promise of business(!!), and the agreed solutions and subsequent AT test results spoke for themselves . We used the PP in key areas only, after a cementitious parge was first applied to all internal ( outer wall ) surfaces. It was primarily used in the window and door reveals to allow the AT tapes around the frames to have something airtight and uniform to adhere to, but was great for getting into acute angles / difficult junctions aka 'nooks an crannies'. Proper tapes and membranes stick to each other like shit to a blanket, and I pity anyone who applies them to areas where they then have to be removed from. The most important thing is to have the surfaces freshly cleaned / primed / dust and contamination-free to allow the tapes to work well and last a very very long time. Mastics, membranes ( liquid or sheet ) and tapes, in conjunction with parge coating can ( and does ) work very well indeed. The devil as always is in the detail.

Did you have an AT test? Parge needs to be done before joists / wall plates go in / on, and before floor ( deck ) boards go down, to get to all the areas that are often overlooked. This kind of detailing is why one project just got 3.02 ach and another 0.88. If going for wet coats vs dot n dab then the parge can just be done to get the interior to a point where the plasterer is laying onto just a ribbon of parge and that will be a top job. To achieve air tightness you need to understand all the places which get overlooked and know where to focus your attention. Very easy to get “almost right”, which is basically pointless starting at all.

That should be the straightest route to a resolve. If you could post back here if / when a solution has been found, and what was done to fix things, that would be appreciated.

Labourers are taking £600 a week, trades double and then some. Some are worth every penny, others are there keeping their heads down and taking the piss. Doesn’t take long to see who is good at their job and which ones have just bought some tools and a tool box.

@dnoble ?

But it is needed for system analysis. Without more information we’re pissing into the wind here, sorry.

Have you not contacted a different PV installer local to you? FYI, there are lots of PV installers, but very few ‘experts’ tbh. I’ve lost track…..do you have an app / portal to see each panel? Or are you only able to glean base statistics from the inverter? How much was / is the “unwanted gizmo” as that may cost the same as a call out and identify what’s going on and give you far better ongoing monitoring / observations. My guess is, that any PV ‘expert’ would insist in removing and checking the panels to be able to assure you / themselves that all is correct / reliable. You’re going to be spending money either way, so if it was me I’d want the most amount of information available to me, prior to, which says get your monitoring up and running to the best it can be and then report back here with that info for any further possible assistance. Or pick up the phone and start getting second opinions……

I set fire ( accidentally btw ) to the menu in the Plume of Feathers lol. Nice feathered steak ? ? Lovely place.

No lol. The OP!!

What make radiators are these?

@graham1 Can you upload a diagram of your exact heating layout , as best as you can, please? This may help to get further replies and possible solutions to your ongoing issues.

@graham1 It is unhelpful and laborious for you to start another thread to discuss this Already discussed and open here for further input……

Too thick for me, but mates of mine use it too.

We run to 2.5 bar cold on the day. If it can’t hold that we drain and redo. If it holds, we run it scorching hot and check again for final operation.

FYI, I have been fitting valves to rads for north of 25 years, and have never ( not once ) had to or would use Fernox ( aka clear silicone ) to make a rad valve off. PTFE and experience is all you need, end of. Fernox is a bodge.

21 turns of PTFE for me in most instances. You can tell if the threads are shit and the number of turns you’ve applied will not get any purchase, so if you’re a DIY’er then don’t beat yourself up……took me a couple of years to perfect this ‘sixth sense’. Are you stopping turning the stem in before the last of the threads of the stem reach the rad?

Isolate the electric supply and check all cable connections. Pull connectors off and push back on ( carefully and slowly ) a couple of times, and retry. After that you’re on the web for a PCB I’m afraid. Judging by the age of the boiler, you were probably on borrowed time with the PCB anyhoo

If you max out the payments. If you’ve decent insulation / windows etc then your EPC will be better and you may only get 50% of that money, or even less as you move towards ‘eco’ credentials.

Not wrong terminology, completely different bit of kit altogether. Just don’t want you basing new / fresh assumptions on the wrong bit of kit