ProDave

I bought a cheap energy monitor and found it to be totally useless with PV and an immersion heater diverter. It seemed to be summing the generated power and the imported power and coming up with a big number when in fact it was at equiulibrium with nothing being exported.

Well done. I would hold back on claim #2 until you have the money for claim #1 in your bank account.

It would be very odd for an AKO drain to drain into a foul waste system, that would as a minimum need to connect via a trap. Even if it does, kitchen sink water might be left standing in the drain if it does not have a decent fall and could get smelly in summer. But most important is what building control will say, I expect they will not approve it. Dig a channel across the drive and lay a proper foul drain for the kitchen waste.

A circulating pump running all the time could use 200W, and that should be obvious by the small noise it makes.

You need to get a clamp on ammeter and investigate what system component is drawing the rogue power.

Hi and welcome. First question is what do your planning laws say about changing use from a holiday home to permanent residence? That would need planning permission here. And what do building regs say about a renovation? Again here, that would require a building warrant and the finished house complying with current regs. If the paperwork does not cause you grief / expense / delay then it sounds like a fun project. It should be pretty easy to repair the frame re clad and insulate from the inside to make a decent building.

Is it really 200W continuous? or 200W averaged over a period? I think we determined on another thread, the Ecodan when it does it's automatic frost protection circulation turns on either the resistance heater or the heat pump itself so will briefly consume a lot more power.

What temperature do you heat the water in the TS to with the ASHP? With our UVC we heat it to 48 degrees. I strongly suspect if you only heated a TS to 48 degrees, you would not get much water out before the temperature was no longer hot enough.

We still have the FIT of our previous house that is now tenanted. we have to get a quarterly reading from the tenant. When eventually we do sell that house, the remainder of the FIT will get transferred to the buyer.

As above, make it a condition of the contract that the FIT contract is transferred to you. Our old house has a 2kW PV system on the original 2012 FIT rate and it pays just short of £1000 per year, so you should get something similar. That will have been a 25 year contract so another 14 years left to run. Then the 2 things to self use as much as you can to further reduce your bills are shift the use of big appliances like the washing machine to the middle of the day (on a timer if you are out) and a solar PV diverter to send any excess to your immersion heater.

It's now vintage. One of the first digital storage scope's made, it cost me a whole £3 when I bought it not working as "scrap" from a previous employer and then repaired it. I have had it 30 years

You don't want a thermal store with a heat pump. For a TS to have any capacity, it needs to store the water a lot hotter than the delivery temperature, which is completely the opposite of what you want to do with a heat pump.

Don't you want some rain now to set the dry mix?

If that statement is true, it would be the complete opposite of the 1930's semi that we once owned. Solid, unisulated walls, meant it leaked heat like it was going out of fashion, cost a fortune to heat 20 years ago, I would not want to be paying the heating bill for it now. We had fitted better windows and insulated the loft but the basic fabric of the house was poor, and little you could do cheaply to improve it.

The indoor electronics bench

I would be interested to see the makeup of that floor. If it were a low floor void underneath it would probably be thin joists with intermediate sleeper walls, but with such a big space under the floor it might be larger joists spanning the width of the room. That would make it easier to insulate properly to a good standard and with a good working space under. Contrary to what most think on here, I have no problem with a well insulated suspended floor with UFH I did that by choice in both my self builds. With that huge space, I cannot see how you can build it up for a solid floor without the infill putting outward pressure on that very large height you have to build up, and that's one hell of a lot of infill to import to do it.

Except if it enters your heat pump at 0.1 degrees and you reduce it's temperature by 0.2 degrees, it leaves in lumps which the heat exchanger and pipework probably won't like. AND it would have to be flowing all the time, even if the heat pump was not operating otherwise it would freeze in the pipes and heat exchanger. Zoot's stream may not get that cold, but in winter ours is snow melt, so barely above 0.

Ah you need a mechanical workbench in the garage, and a completely separate electronics workbench in your nice indoor workspace (aka the plant room) I don't think i have photographed that one yet so I might later on, if it's not too untidy.

I did briefly think about a water source heat pump from our burn, but to extract that much water (even if it goes straight back slightly chilled) would need an extraction licence and I could not face even attempting the paperwork to get permission. One alternative might be a heat exchanger, aka an underwater radiator? Our burn never freezes, even in winter it is flowing but with ice forming on the banks it can't be much above 0 so not a lot of headroom to extract energy from it or you will be pumping ice cubes back into it.

The BC thing is so variable. Here in the Highlands, BC wanted to inspect and test the foul drainage several times, but did not look once at any aspect of the rainwater drainage.

Just read the regs carefully. In Scotland, the half or quarter landing has to be at least as wide as the stair, so 900 stair and 840mm half landing would fail.

All stairs must rise the same amount, so you can't have one shallow step, make them all the same. I am also pretty sure the half landing must be as wide as the stair, so if you can only fit a 840mm half landing then probably the whole stair will have to be 840mm. Is that allowed where you are ? (In Scotland the minimum is now 900mm)

No 1, while they are in storage, strap them together or lay them on a definitely flat floor weighted down to try and keep them straight in storage. Are you fitting them to block walls (I guess so looking at the picture) My No 1 tip is adjust the door linings to match the width of the actual doors plus a few mm. Doing that, I did not have to trim any doors.

Take a good look. It is rarely that tidy. The rear wall has OSB before the plasterboard went on and just nails to hang the tools on, then drawn round them with a big marker pen.

I have worked on many Grant Vortex boilers and I have NEVER seen that valve used like that. There should be a normal fill loop with a valve each end to fill the system with water until it reaches the correct pressure, then you turn the water off. I SERIOUSLY think you need a different plumber, I think what the existing one is telling you to do is wrong and possibly dangerous.