JohnMo

You don't really need have to work out the kWh, you need you understand the kW required - the power. The boiler is already way bigger than most heat pumps, so not seeing much issue. To understand better you need to do a heat loss calculations for the final layout of your house. There is spreadsheet in the boffins corner that's quite good. Tying it into the existing system is pretty straightforward. Here is the advise from Bosch using close coupled tees. CCT WORCESTER BOSCH.pdf

8.5kW heat for 2.5kW sounds like overkill, you will need a decent sized buffer to keep it happy and no more than one zone. Or if you have UFH and decent depth of screed batch charge overnight.

Our last house circa 1820 build, we had a full replumb, plumber sized the radiators and said we need 4 or 5 huge radiators in our lounge. This forced me to do my own calculation. Ended up with 2 radiators, no issues. Very little engineering going on, monkey see, monkey do.

If it is 2kW, you don't really get a heat pump that small, if you did DHW would take to long to heat up. You need to look at the output at your design temp to see what matches, they all quote different kW outputs, one may do 5kW at -10, while the next may do 5kW at plus 15 and only kW at -10. And are rated as 5kW. MCS assume you don't have MVHR and will not include in the calculation. Realistically it's going to be an ASHP in the 4 to 6kW with a buffer

Just the opposite with really you the end user live with short cycling all year and the energy cost hike.

Again another real example of shoddy plumbing, and UK treated shoddily. A combi in the UK has a flow restriction in the cold water pipe entry to the boiler to compensate for cold water in winter. A small 25L preheat tank, the flow restrictions is not required. I was able to run showers off my combi, shower experience is exactly the same as my now install UVC.

Have to agree. My combi boiler when installed, used twice the calculated gas in year one. Lots of changes later I was on par with calculated/slightly better due to condensing.in year two.

Conventional R32 and prior to that refrigerant would use two or more stages to boost the temperature higher each stage. Current propane refrigerant can take the water to 75 in a single stage, with most temps up that at a good efficiency. CO2 refrigerants do really high temperature in a single stage, but do not do lower temperature at all well.

@Roger440 Why does everything always cost £10s of thousands. It not a case of all or nothing to insulate. Hit the biggest things first. Drafts, lofts, rooms heated hottest next. Bedroom and windows are long way down the list of jobs that give any value. Insulation is like most things you get a big jump in energy saving for very little cost, then to get those extra few percent it costs a small fortune and most cases isn't worth while. You have an oil boiler, make sure it's operating in condensing mode, most or all of the time, that will around 20% efficiency or 20% reduction in oil costs. If you have to replace a radiator swop for a fan coil or fan assistance radiators instead of like for like, slowly move over to more energy efficient heating, that can operate at low flow temperatures. Get a heated jacket - if you have to open any big doors all the heat has gone insulation or not. Use outdoor UV heaters to you not the air.

Hager

Plus most pay zero UK tax, I believe Shell for example of paid zero tax in year April 23, but actually got tax revenue to do stuff.

UFH, dT15 (big) radiators or fan coils are the only way to get a good SCoP. No they guarantee a SCoP of at least 4. CoP is instantaneous, SCoP seasonal.

Mine are the same, stopped using them, just plugged in the 3 pin plug instead.

My view, Would or did I bother - no Is my life richer or poorer with or without smart switches - no, make little or difference either way. Not difficult to flick a switch as I enter or leave a room. Future proof - no Could company remove functionality of the switch - yes if a cloud based system Short life when installed - possibly, see examples above Will I be able to get spares easily - who knows, will company or the same part exist in 5 years time? Will it cost more to install your lights - yes Will you use all its functions after 5 days - most possibly no Would your other half or a new owner of the property or an electrician fix easily if you are not around - maybe, most likely not. Can you or the electrician get spares today - most likely not. Can you switch your lights on if there is a hardware or software issue - maybe not. Have I got home assistant - yes Do I have smart relays - yes Are they the best thing ever - no, great sometimes. Are smart things a good thing, not really keep it simple - KISS

Basically what happens the mixer closes (goes in to full recycle mode) and a microswitch in the actuator switches the pump off. All wired as ESBE recommend. If there is a heating demand the mixer moves to allow hot water into the system, the microswitch switches on the pump. This is the remote controller, they either come as wired or wireless. You can change settings and see what the water temp is downstream of the mixer. ESBE do lots of variation, with subtle differences.

UVC with large heating coil, circa 3m2. Size to suit the property, heat to between 47 and 50 from heat pump. I heat mine at 6am on E7, takes 45 to 70 mins, depending on its start temp and a top up if required at mid-day. Keep it simple.

- Most MCS installers weren't taking the pi** with pricing?

It's likely to be the expansion vessel has a leak or needs a recharge.

But those windows are not misaligned. Vertical alignment is present so is horizontal. He also isn't building an old building? Or is he trying too? The windows on SE and NW do not have vertical alignment. It looks odd in my view.

Concider getting fan coils instead of radiators, fine for heating and cooling. Smaller than a radiator, flow temps similar to UFH (35 degs). Faster response than a radiator due to fan assistance.

ESBE do a range of controllers that go with their 3 port valves and actuators, not cheap, I bought all mine for peanuts off eBay. Mine is set up to run on pipe flow temp mode. It has two set points (T and T2) I trigger the two different temperatures via thermostat. On a call for heat (T2) I allow it flow up to 36 degs, once thermostat senses house up to temp (T) is set to 22, it moves the 3 port to full recycle and switches off the pump. Early image without insulation. With underfloor heating there is zero advantage having an App controlling anything, run time are too long. If you want to switch your heating on before you leave work, your going to cold all night.

It's all rubbish really when you see how much industry looses per year via small (!) leaks. Doing an improvement project for one offshore site, they lost the equivalent of 300 tonnes of CO2 in a year, through so called small refrigerant leaks.

You have a lot of glazing on the north east elevation, not the best aspect for glazing as zero heat gains, just heat losses. Will you ever get enough sun to make you want to sit out on the balcony areas? Are they all north facing? Internally not sure why you have a plant room and waste upstairs space by having a cylinder up there, put it in the plant room. Both end elevations have miss aligned windows - it look wrong and badly thought out.

What do you mean? A layer of 9mm ply laid down, second layer on top with joint lines of the first layer overlapped by the second. Once glued and screwed together will become a single piece of ply 18mm thick. With staggered joints there are no weak areas. You make the ply floor smaller than the room so it can move (float) to allow it to expand and contract. Just add it, it's not doing anything as a VCL as there is nothing to protect from moisture. It's just a slip membrane to allow the insulation and ply floor to move independently of each other.

You have a dpm, so not sure the vcl is actually what you are calling it. If you do add a polythene sheet it will effectively become a slip membrane to allow movement of the flooring above - a good thing and cheap to do Either two layers of 9mm ply staggered joints glued and screwed or as specified 18mm. The 2x 9mm with give a single piece floating floor. Both versions the floor should be made 10mm smaller all round than the room walls, so it floats and can expand and contract easily.