JohnMo

Or do a hybrid, 3kW would do a big lump of the year, the heat pump can drive an aux heater, so you could configure to hybrid mode very easily. Just put a PHE in the heating circuit on its secondary side and a loop from another heat source on the primary side.

If you have internal space or shed something like this. https://trianco.co.uk/activair-indoor-9111-9111 Run at a fixed unit temperature. It's mounted internally so no need for any planning or permitted development palaver. You could even hook up the exhaust side of MVHR to strip any useful heat out of that (after a bit of due diligence) in winter and take a CoP gain. Leave your DHW as it is.

The same way as you choose to live there, no one made you rent there, you could have chosen a different place to live. Again you would have seen all this, before you signed on the dotted line, and paid the deposit. If you don't like it, move noone is making you stay there.

Definitely the 3 port diverter before buffer, the buffer is there for the heating system only - but only if you need it. I would have the ASHP controlling the the export diverter - it will have an output to control it. Good thing about a 2 port buffer is water only flows through it if required. Otherwise it's just bypassed. You set up the ASHP to control buffer temperature, any room thermostats would control the UFH pump, or secondary circuit circulation pump. Heat pump continues to run even if no call for heat until buffer temperature is satisfied. As soon as a zone has a call for heat warm water is drawn from the buffer by either the UFH mixer pump or secondary circulation pump. Once the buffer temp is lowered the thermostat on the buffer calls for heat from the ASHP. LLH and buffer are the same thing as drawn, just the buffer is a bigger volume. Both can lead to primary and secondary circuit distortion and mixing between flow and return leading to a drip in efficiency. Mixers need or not, depends on the design flow temperature and variances in flow temperature between floors, if they are all the same maybe no mixers are needed. If they are different you may need mixers. The other thing is number of loops and required volume flow and system pressure drops - can your ASHP circulation pump handle it. If not you do need hydration separation and a secondary circuit with its own pump. Snippet of information is all well and good, but solid facts are really needed. If you are going for a grant via MCS, your hands are somewhat tied anyway. You need to do a whole system design as a one off task, a bit of and bit of that really isn't good enough. There seems to be some misinformation out there, that heat pumps shouldn't cycle. All heat sources cycle, it what they do to manage loads below minimum turndown. There's a difference between controlled cycling and uncontrolled cycling. If you heat pump runs for about 10 mins or more the cycle is controlled, running for a couple of minutes or less it is uncontrolled (or short) and a piss poor system design. Minimum information required Total house heat loss Floor by floor heat loss Number of zones per floor (how many thermostats) Number of loops per floor - ideally with loop length or flow rate and each floor design flow temp.

Why? You really don't need any cooker hood on daily basis with MVHR it does all the work. You only really need it occasionally.

I would check that down pipe for blockage and the joints leaking when it rains.

Either you are leaking heat like a seize or you have input the wrong numbers somewhere. Would look at air changes first. If you have MVHR set at about 0.3, if no MVHR set at about 10% of your air test result or target at 50Pa.

But the EPC cannot take this fact into account. As I said it a comparison tool nothing more nothing less. By using a time of use tariff and smart control. A more typical 8 kWh of hot water on E7 could be closer to £3-400 per year at 14p per kWh. Not really much additional kit to have an unvented cylinder heat pump heated, if buying either cylinder new, £100 uplift in cost compared to immersion only and it may (mine did) come with a 3 port diverter. Connect diverter to heat pump and temperature probe to cylinder - you are heating via ASHP. No buffer or additional control required.

Not sure about that, although @TerryE has the skill set to set and manage direct heating to be cost effective, many people don't. The next owner could just change to a standard tariff, switch the heating on and then have to live with the cost. Which is going to 4x the cost of gas or ASHP. The EPC system is just a comparison tool, flawed but ok in most cases

You are likely to have 3 different floor buildups, so three different flow temps. So would suspect mixers are required. Not sure you need all the pumps, 7 in all including the one in the ASHP. The ones on the mixers should be good enough to pull and push the water from the buffer without intermediate pumps also. Mixers do not entertain any other mixers than IVAR (mechanical) or electronic driven by Vaillant controller. Buffer - really depends on how you intend to operate and the flow rates and min engaged volumes. I would only do a 2 port configuration, not a 4 port.

You would be better profiling the support to skirting. Polyfiller I suspect would crack and fall out or just look rubbish quite quick. Someone mentioned a non shrinking decorating caulk about a month ago - that maybe of use, no idea the name of it through

Really depends on how solid you want it to feel and how they are supported and the span they have stretch across. Outs is off the ground so attached to ground in a limited way via pillars. Most of ours are in in either 47x225 or 47x175 on 400mm centres. The 175mm can span about 3m or so and the 225mm 4m+. If on the ground mounted as other responders have noted.

Inverter seem to be cheaper also, not sure about diverters

Maybe in some other universe, or where ambient is constantly 30 or above, but I wound prefer 16. Airtight and even with 0 outside the other night, we had the bedroom window open.

Small area, normal pumped C35 will be fine, sounds like the ground worker are looking for an easy life, but doing a smallish slab isn't that difficult, with the right tool (even without them)

For export and being paid it's MCS. Octopus say they will accept you but not really unless you are willing to pay a minimum of £250 sign up fee for the trial (that's a lot of expert to get that money back) Check out City Plumbing first for pricing before you commit to used prices on eBay. Everything is getting really cheap new now.

Good luck on that one

We just don't heat the bedroom, close the door and open the window (for the last 6 weeks anyway)

Just set the flow temp to say 32 in loop cad it uses that to calculate the floor power. As @nod says the loop spacing only really make a difference to heat up time. But once heated you keep it heated for the heating season - you don't let it loose too much heat. Doing setbacks is a waste of time with a thick screed (you will end up with one). So don't go overboard, just do everywhere the same spacing. Keep one pipe spacing away from outside walls, and don't bother with pipe under stuff would be my advise.

Viridian - there's a box on the video.

I assume the trees would need permission to be altered or removed, it's also gamble the council may say NO! Plenty of other houses with less hidden surprises, just move on to the next one.

How is your piping run down you have flexibility pipes between ASHP and house? Anything solid will transfer vibration.

The shelly is just a wifi relay with manual switch input as well. You can use the shelly app to set timers to open and close the relay contact. Use the output of the shelly to control a second relays open and closing solenoid - choose a relay that can happily take 13A continuous load, it can be a dumb relay. You can just use a light switch to do the manual override.

Yes, you house will almost use anything first anyway.

I really wouldn't bother. You need UFH flow way lower than radiators. Plus plenty of insulation under it, otherwise it's pretty rubbish. If you want to take the chill off the floor use an electric heating mat under the tiles. And then just fire up as you need it on a run down timer so you cannot leave on for weeks.