ProDave

Don't be so quick to condemn it as "not needed" and "the house must be leaky" I previously had a 1930's semi and when I moved in it still had the open fire, which for a while I used as there was not much other heating (it was a doer upper). I soon found that when you lit the living room fire, there was no provision for air in, and the easiest route if could find to pull air into the building was down the upstairs chimney into the bedroom, down the stairs and howling under the door. On a still day with no wind to take the smoke away, it would even draw smoke down the bedroom chimney into the bedroom. To avoid a draught, you could duct from the air intake around the room to the fireplace. Or if a suspended floor, make an air inlet vent in the floor right next to the fireplace.

The Generation meter will tell you how many kWh the PV has generated in total. The GroWatt inverter has a little display on it and if you push the buttons and cycle through the display options one will show you at any instant how many watts it is generating right now.

Not understanding the question?

Room sealed stove with a duct from the air inlet through the wall to the stove. Should have asked here first.

Just watch out that all that surface water (high water table) cannot get into your treatment plant and overwhelm your pumping station and soakaway.

Probably some residual air in the system, it will whoosh or gurgle each time it comes past the pump. If you have an automatic bleed valve it will eventually self purge.

I hope the Llangollen is staying where it should be and not trespassing on your garden.

Simple answers yes yes and yes. If you are having all UFH then perfect. An ASHP will heat DHW in an unvented tank, avoid a thermal store, they need water stored hotter than an ASHP is comfortable with. Most of us heat the DHW to about 48 degrees which is plenty hot enough for use but not as hot as a gas boiler would go, so we tend to use a slightly larger HW tank. Don't order the ASHP until you have a proper detailed heat loss calculation so you know it is sized to the size and insulation of the house. they WILL be lower power than a gas boiler so it is important to get the size right. Mitsubishi Ecodan is a popular choice and not over expensive and I have not heard anything bad about them. There is the "discussion" whether to get an MCS install and claim the RHI, which might not be very much for a new install, and might have finished anyway before you get there, or just buy it and get your plumber / electrician to fit it. If you are thinking of using it for cooling, as well as the UFH you might want to consider a couple of Fan Coil Units mounted high in the building to deliver chilled air (just like an AC unit) which is more likely to chill the whole house than just running cool water through the UFH.

Nothing has "priority" you are over thinking it. The inverter will spit out as much power as it is able to depending entirely how much sun is shining on it. Your house will use as much energy as ANY appliance turned on needs to use. If generated power exceeds power being consumed, then to prevent power being wasted exported, your device will send that power to the immersion heater. It can send anything from a few watts up to the full nominal 3kW to the immersion heater. In the winter the heat pump will use almost all that you generate, but even so, there are times when it is idle and I have seen power going into my immersion heater. The appliance thing is more for the summer, when you are generating most PV power but apart from DHW heating, the HP is not doing much. I have my HP timed to not start DHW heating until 11AM by which time there is a fair chance the PV is generating a good amount. But we also use the 3 big appliances one at a time around the mid day slot to try and self use as much as possible.

Yes that is the whole point, they only send to the immersion heater the excess power that would otherwise have been exported. The best use for solar PV is to use it for something more useful, like do all your washing, dishwashing, tumble drying in the daytime close to mid day one machine at a time.

Have you tried turning off all but one radiator and seeing if just 1 radiator running will reach 55 degrees? Or am I wasting my time trying to help?

Hello, yes Flat 1205, 12th floor, can you come and service my air source heat pump please?

For me the disappointing thing in the wish list is the air test number. I see SO MANY houses, even recent ones where you unscrew a socket from the wall and a howling icy cold gale comes out of the hole. It is my gut feeling that the best "bang for your buck" improvement would be force the builders to sort out the air tightness and install mvhr. The air tightness is not so much of a cost issue but an attention to detail issue.

Just one or more 16A sockets. Contractors will bring their own 110V transformers. As early in the build as you can makes sense. And remember to give the site sockets their own TT earth NOT a PME earth.

I will stick to my boiling water tap.

I am 5 years into my build and nearly finished.

Welcome back. You see the self build bug is adictive. They say you probably get it nearly right by No 3.

Thanks @newhome

Back in the day, it was a trademark of a BR craftsman that all the screw heads were lined up. Of course the engineer would argue by doing that they cannot possibly all be tightened to the correct torque.

See my post earlier. Turn off half the radiators and see if the ones left on get properly hot. That will start to tell you where the problem is. Or even more extreme, turn them all off but one. That one left on should have no problem getting properly hot. If it still does not then something is set seriously wrong with the ASHP. If that one radiator gets properly hot, turn on another. do they both get properly hot? If so turn on a third and so un until you reach the point they can't all get hot. Report the findings.

35 degrees is barely tepid. I would have expected radiators to be running certainly over 40 degrees. If that is the hottest it can get them, it rather looks like the HP is struggling. Turn half of them off completely and see if the half left on get any hotter than that. The small difference between input and output is because they are so cold barely any heat is leaving them into the rooms.

Jewsons do a trade account for self builders. The only reason I had one was they were going to slap a delivery charge on for cash sales. I can't say it made much if any difference to prices.

Who built the house or have you just bought it like that "unfinished"? What is the sides and top of the recess made of, looks like plasterboard to me. Normally you would have a stub of flue pipe and a register plate, but I am not yet convinced that lining is fireproof, and I would have expected the flue liner to be encased in insulation like vermiculite but there is nothing to hold it in, so I suspect not. I would be having words with the builder.

I would love to see a description of what an ASHP "service" actually is or hear from someone who has witnessed one done, as to actually what they did. All I can think of is a visual check to make sure the air flor is not blocked, a functional check, and check the pressure in the heating loop (though the latter is not really an ASHP service) Snake oil springs to mind, but I am a suspicious person.

Does the drawer close? If so that should do nicely.