JohnMo

Why not replicate the existing house with wood fibre IWI? Not a fan, too easy to make a dogs diner of it, and effectively make it useless. Disadvantage of IWI is you make the build thermally light, so temperature can yo-yo over a short time frame. It very limited thermal capacity. Or just go with a bigger cavity, heavy blocks inside and out, and either poly bead or mineral wool or similar cavity fill. Then just plaster, not sure what the parge cost brings to the party if your plaster anyway?

Me neither, every start equals wasted heat out the flue and stabilising metal work temperature, instead of real work heating the house. Long runs equal efficient use of gas.

You would drive down your pumping losses with a wider dT. But suspect they are low anyway. Your current mean temp is 29, the 40-28 drives your mean temp to 34, wouldn't you start to over heat the house quite quickly? To run 12 dT, and keep the same dT across the radiators wouldn't you be closer to 23 and 35? That would give an additional 3 degs of condensing and about as low as you could go. But whether you could actually get that low in practice is questionable, not sure you would ever get a permission to restart after a heat cycle, as return temp would never drop low enough. My Atag, with it's modulating pump and 32 flow would have been running 4-6 dT, like it or not.

Maybe simpler to do it upstream of the combi rather than after. Then small amounts of temp rise give massive uplift in flow rate. Combi-SuperFlow-White-Paper-v1-2-4.pdfCanetis-SuperFlow-Product-Sheet-WE-050318.pdf You can also do it way more cheaply than a mini store. As a mini store is based on heating medium in the cylinder and domestic water in the tubes. So you really need to connect the combi to system boiler for the proposed to work.

Why would you install with a gas combi? Tell us what you are trying to achieve?

Unistut copy from local electrical factors (Medlock), comes 6m lengths.

I would want a number, otherwise it's meaningless. Getting towards something is very open to interpretation, scoring 6m³/m² @ 50Pa is getting towards passivhaus (it's nowhere near) compared 10. You possibly thinking under 1.0, so there may or may not be a big gap of expectations?

Steelwork modified, using 41mm square channel, two panels in place. New array

Call your installer

Panels now upgraded, photos tomorrow. Day one, took 12 panels off the hill Day two, very windy, modified the steelwork for new panels Day three, new panels lifted up hill and installed, reused all old wiring without issue. Switched it on and all worked fine. Materials 2x 6m lengths of 41mm galvanised channel 12 panels 28x 30mm panel end clamps.

That is pretty easy for most builds. One caveat, you and everyone else are working to the same drawing revision. People change stuff, they assume because they know, and the architect knows, everyone does. I had final sign off on all drawings for the build, once our building warrant was approved, no drawings got changed, no details where changed. But that isn't the case very often. So dot you eyes and cross you tees.

Make sense to have something obvious like a DC isolator to kill the PV at ground level outside - I have a DC isolator outside near the front door. Isolator hidden in the fabric of the building or in a loft not easy for anyone. If switching under load kills the inverter who cares.

Keep seeing these threads, and still see zero point with most of what people do with automation. Waste of time and money. But fill your boots. My current lighting scheme, is side lights in the lounge from a normal light switch and 3A wall sockets. Don't need home assistant or shelly or any other smart relay. Got a box of them, all removed, in my cr@p I bought box and was waste of money. 4 years in house, no smoke or heat alarms have ever gone off. They will all be binned at year 10 and replaced with new. If they go there's an issue. Heat alarms in kitchen don't react to you burning your toast.

But it has a modulating circulation pump which will change output based on dT, so not sure that can be fully true. If 14.4kW isn't enough the return temp will always be low. So if the boiler has been range rated to 40% it will constantly chase it's tail. So @EinTopaz what is the boiler range rated too?

So, boiler will have a target flow temperature with overshoot hysterisis. But, it also has a control set point for dT. The circulation pump and boiler modulation will adjust to maintain dT then add more heat as dT closes down. I suspect the heating system return temperature is holding everything back, but this must be at or close to target otherwise the boiler output would not modulate down. So boiler is doing what it should it has a decent run time, it's modulating down, it possibly massive for the duty. Other than a desire to have radiators you burn yourself on, I don't see a real issue.

Do you want a hot house? Is it getting to target room temperature?

Do your add on temp gauges have the sensor in insulation, if not you will read meaningless numbers. To get them to read close to correct, you need thermal paste, aluminium tape and covered in insulation.

So really confused - what is the issue with that? Is your house warm enough ?

Give it a good clean, it could be the plumber never cleaned the flux off. Bit of soapy water and abrasive pad. Dry it off. Then leave for a few days, with the joint wrapped a kitchen paper towel or loo roll around the joint and inspect, it will trap any water and stay wet for ages, rather than just evaporating off. If it's dray and stays dry for a couple of days it was flux. If wet the joint is leaking.

They can't do it, they can only use the information stored under your MPAN. You have to go through correct MPAN database to change address. We had to do similar, call your network installer - DNO (ours was SSEN) and they will point you in the correct direction. From what I remember it was quite straightforward.

As mentioned above a flow sensor needs a system clean, and it needs to be air free. It seems to be the norm to install strainers, which pretty rubbish at stopping small stuff being circulated. You said you put cleaner in the system the other day. I would now look to flush that out, give the flow sensor a good clean. Refill, inhibit and biocide the system (biocide if you do cooling or routinely run below 35/40 degs. While you are at add a decent low flow resistance magnetic filter and delete the strainer.

My be worth reading this, not reread it all but may be something of help https://forum.buildhub.org.uk/topic/30786-lg-therma-v-monobloc-ch14-flow-error/

But this mechanism is to protect the boiler, nothing more nothing less. Short cycling is just a quick way to empty your bank balance. You heat the boiler, pipework and a load of energy goes out the flue and maybe you still have a cold house. If you boiler is in that mode, you maybe have way to many zone, badly set up heating system, or another issue, or all the above.

No. Say your inverter trips out at 253V, grid on that day is already at 250V. On the AC side the inverter, it pushes out grid volts, plus a bit, otherwise it cannot break into the grid. If you take all the voltage drops on the AC side the inverter adds volts to make sure it can break into grid, plus it adds the voltage drop. So on a high voltage day your inverter may trip off. It does care what volts it gets on DC side

Run long cables in DC, so they take any voltage drop on that side, (less of an issue for the inverter - doing on the AC side cause high AC voltage and it could result in the inverter tripping. When I did my install PV rated SWA didn't exist, it now does. I ran my cable on the surface - easy to see and less likely to get accidentally damaged. New panels are generally maxing out at nearer 14A. The panels will generate full voltage even in low light, the amps increases with more irradiance. Find a DC voltage drop calculation online, I used I thing 6mm² for about 40m.