JohnMo

As mentioned above, for a boiler or heat pump to run for a decent period of time i.e. not short cycle, the heating system requires a given volume. The boiler or heat pump will switch it's self off, when the return temp is too close to the supply temperature - delta T is no longer within the prescribed limit. This happens quite quickly with a system volume that is too small. The boiler or heat pump doesn't care how the downstream system is configured, as long it's working volume is adequate or in the case of a hot water cylinder there is enough volume in that to move the heat away and the return temperature is within a defined range. Your system as drawn is really a hybrid of a heating system and cylinder. There should be no reason why it would not work. The other option is to instal the conventional way across the supply and return and then split the zones after the buffer, but this would make your two zone box a single zone box. One thing I thought about while writing this, was if the buffer (as drawn) had a coil in it you could run cold water through it, to pre heat the water before it enters your hot water cylinder.

A stool is exactly what it sounds like. Just something to lift the cylinder above the floor. In your case build a platform wide enough to straddle several joists, use 4x2 or 6x2 and some ply on top.

A buffer would normally sit between and be connected to both the supply and return. But can also be done the way you have draw it, the buffer should be vertical and the bottom is connected to the heat pump as drawn. Your way adds system volume to the whole system and/or to the zones that heating.

Sorry read this question about 6 times and am struggling to understand what you are asking, not sure what the photo is trying to show?

We are in Scotland so not directly affected by the English legislation, but... We have built by a Loch of Special Scientific Interest, which has extremely strict requirements on nutrient inputs to the water body. With this comes a boundary line, where anything water born can make its way by natural drainage into the loch. This line of influence depending on elevation changes can be several hundred or ten of metres away from the loch water edge. Our house is within the influence line, but our treatment plant (which has strict output limits) has to discharge outside the boundary line, to a soakaway 100m away. Luckily we have the land, but within our plot there is only just enough room to install the soakaway. So things can be done, you just need to armed with the information before you proceed with a purchase, near water.

Not sure how pretty you want it. But I used glass wool in the rafters, then sheets of 25mm PIR screwed underneath. Ran electric cable in conduit to strip lights below the PIR all visible.

5m head in this case isn't the height difference as you have a loop, as the water would find its own level, imagine a 'U' tube. The water coming down will be pushing the other water in the circuit up. So the 5m is the head loss from pipe friction and bends. I just time mine on for 30mins for the morning, as get up the same most days and the same in the evening. But I would be tempted to work out how often your cylinder would initiate start the heat pump to start running circulation continuously. I think you will be surprised, as I don't think it will be that often (every few hours). But insulation on pipes would be a good idea.

2x 50l?

I would say wall hanging needs to be designed in by the manufacturer. Generally thin wall pressurised vessel weighing more than a 100kg.

I'm using a Lowara Ecocirc Pro pump, which has an integrated timer. Works great, real easy to install, just power needed. Several sizes are available.

We have 190m2 with a spacing of 300mm (more normal is 150 to 200mm). We have about 400m of pipe in the floor, which approx 46 litres. A close estimate would be to double my volume of water, divide by 190 then multiply with your area. A 6kW min load of a boiler/ heat pump requires approx 125 litres, for a 10min run time. Use the calculations in MCS manual I linked to earlier for the calcs. Hope this helps

As self install or non MCS install, you will not get paid for export, so doesn't really matter what occurs during export. With a 2kW array and I assume an immersion diverter, you would be very unlikely to export, except for a few weeks per year if no-one is home during the day. If you hoping for export payment, you need an MCS certificate to be eligible.

Looks like they continue to trade, hopefully someone will take over.

Bit of a worthless and obnoxious comment. I certainly had no issues with the product or the company.

Joules do a unit that's on the top of a tank or standalone and can provide the level of heating you require also. I think you have to go through them direct as I never been able to find a price. There is no outside unit, works as a MEV system (combined continuously extracting) so single hole in wall. Or you could take in external air also I would think. https://jouleuk.co.uk/victorum-exhaust-air-heat-pump-compact/ https://jouleuk.co.uk/victorum-exhaust-air-heat-pump-pre-plumb-system/

Bit lost with this. Currently sat on a leather and wood chair, on a wooden covered floor, all of which are insulators, so even if my slab was or wasn't earthed, I am not. The same would be true if stood bear footed upstairs in a timber kit house (wood floor support of wood structure). So what's the difference if your slab is or isn't insulated from ground contact? The UK has earth cables connected to every socket and switch in the house and these are run to earth. All conductors (copper pipes etc) are run to earth. Rebar should be covered by a min of 25mm of concrete in all directions, otherwise it suffers corrosion. So is not accessible. Might be needed in countries where an earth isn't routinely or mandatory to run - maybe USA? But seems a waste of time here.

This is Scottish Larch, installed last May, and oiled a week before the photo a couple of weeks ago.

I read today from the contractor recieving approval for voucher there is a 3 month time limit to get work completed. Otherwise the voucher is lost. They have to reapply against set number of vouchers being offered per year. https://www.heatgeek.com/the-boiler-upgrade-scheme-what-you-need-to-know/

Not sure that complies with the regs, as you would require a gateway and full time display also. So more like this. https://scotlandhomesafe.co.uk/products/carbon-dioxide-and-temperature-monitor

The post 8 hours states CO2, you then said the spec was wrong without further explanation. Scottish Building regs require a CO2 monitor not CO2 alarm. So the word alarm is incorrect. Also in Scottish Building regs the use of combined heat and smoke alarms are not allowed, as only a heat alarm is allowed in a kitchen. It even makes a comment about combined units in a kitchen will not comply with the regulations.

Are you sure you are correct stating that. You need CO for any combustible appliances, gas boiler wood stove etc. It is also mandatory to have a CO2 if your airtightness is better than 15. This is a stand alone monitor mains powered. https://www.gov.scot/publications/building-standards-2017-domestic/3-environment/314-ventilation/ Section 3.14.2 applies

Not sure why you should hit UFH pipes as the pipe should a couple of hundred mm from wall edge. Would lead to a substantial thermal bridges. Our structural walls were thermally broken, with aircrete blocks and 65mm thick concrete bricks on top.

A lot of the rules depend where your house is located, England, Scotland etc, town or rural and the speed limit at your entrance. Your local Authority should have a road design guidelines document, this where you will find all the information. It should be available online. The general way it works is, you must be able to be stopped on your driveway with the gates closed and the front of the vehicle be off the road. - so gates are setback from road edge quite a bit. Then from the drivers seat, you should be able to see left and right what is coming down the road. The higher the speed limit the further you have to be able to see.

Missed that one

Sorry ours is a Harquin treatment plant and there is only one connection to the compressor. No solenoids or timers.