ProDave

Low Smoke and Fume cable I think is horrible stuff to work with, the insulation is much more stiff and springy than normal cable. https://www.screwfix.com/c/electrical-lighting/cable/cat8960001?cableproducttype=twin___earth&conductorarea=1_mm_&cm_sp=managedredirect-_-electrical-_-1mmtwinearth

Not all of them do separate from the fixings. But you have straight access to the screw head with the seat down so that is normally not necessary. Your issue is the screw spins, so the threaded insert in the expanding plastic bit is spinning. It is either brute force to pull it out destroying the expanding plastic bit, which you are replacing anyway, or try and apply upwards pressure between the flat metal plate and the pan, e.g with a flat screwdriver, to try and put pressure on the screw as you try and undo it. the main thing is not to damage the pan. This is the price you pay for concealed fittings, brilliant when the work, but a pain when they fail and you can't access the hidden bit that has failed.

Ah so not fixed wiring. A small round flex will do, probably 0.5mm is okay it all depends on the terminals in the light fittings and what size cable they are comfortable with. It's the downlighters that will be the pinch point. Do they actually have terminals for 2 cables to loop through properly? Many don't and you get just one set of terminals to fit 2 cables in, and a cable clamp really only designed to clamp a single cable.

Define what you mean "for lighting" 99% of lighting wiring done by electricians is done with 1mm twin and earth.

The ASHP will only do one LWT at a time, so to do that you would need to run UFH or radiators one at a time, alternating. Is that really going to work better than just keeping the radiators at a low temperature?

Neither am I. In nearly 4 years, I have exported a total of 334kWh which is just the times the inverter generates more than the house uses, even with dumoing to the immersion heater. The point is the DNO are only interested in how much could be exported, not how much will be exported. They take no notice of you actively trying not to export. I will delve into this more after April when it becomes clear how the new system works in practice.

Best not show a picture of a vintage test meter then. Wait until after April. If your test comes out worse than 0.18 ohm, then they will likely say you need a network upgrade. If you applied for that today, there would be a cost. But it looks like after April you may not have to pay for network upgrades. See this thread: I will be watching for how people find this situation after April, I would like more PV myself but don't want to pay for a network upgrade that I don't think I actually need as I have no intention of exporting anything.

A SAP assesment does not tell you the actual heat loss of the building at different temperatures. Be best it does is tell you in the coldest month is uses 976kWh so that's 31kWh per day or an average of 1.3kW continuous. If that is to be believed, the 7kW ASHP should be plenty. Also on that basis, you can probably get enough heat into the house by lowering the flow temperature and running it for longer. That would be the first thing to try and see if it improves the defrosting.

If you want to try yourself, you can get old loop testers for peanuts https://www.ebay.co.uk/sch/i.html?_from=R40&_nkw=loop+tester&_sacat=0&_sop=15 But they will be out of calibration. Question is, what paperwork do the DNO want? Just a figure? or a figure backed up by the instrument serial number and calibration certificate?

Yes this is all pretty normal stuff. This is the period property version of the "plasterboard tent". As you rightly say cold air from the loft fills the void. You should be aiming to fill the top of that gap to the loft all the way round, but it will usually be a miserable job and parts of it particularly in the eaves may be hard to reach.

0.18 ohm loop impedance is a pretty low target. You would have to be quite close to your substation to achieve that. We only achieve 0.24 ohm and rural properties here I have seen as high as 0.4 This is a simple test that any electrician can do for you. The trick with paying someone to do such a short test, is to find someone really really close to your home, or someone prepared to call in on his way to or from another job so you need to be flexible with your availability.

As an experiment, turn off the heating to part of the building, so it is say only heating the UFH part or heating the radiator part, and see if it achieves the target temperature and how much defrosting it does. This might give a clue if trying to generate more heat than it it capable of is the problem.

Where is the hot water tank in relation to the bathrooms? There is a trend for heat pump installers to fit the hot water cylinder right close to where the heat pump pipes enter the house, in many cases a very long way from the point of use. any plumber worth his salt would be advising put the HW cylinder as central as possible to the points of use to minimise the length of pipe and then use thinner pipe like no more than 15mm to minimise the volume of water that must pass through before the hot water arrives at the tap.

I would not do that. Just tell your solicitor what you have and let your solicitor and the buyers solicitor discuss it between them. You then either complete the sale or the buyer withdraws, only then would I take the action you suggest.

Frequency of defrosting is also a function of how hard the ASHP is working. My 5kW LG rarely defrosts when it is just driving the UFH but is much more likely to do so when it starts heating the DHW where the load is higher and the delivered water temperature is higher. Mine is also on the S side of the house where it is always a little warmer. In a still cold winter spell of weather, the north side of the house can remain frozen for days on end, but it only takes a little sun to warm the S side of the house. What may be more relevant from one make to another is how the defrost cycle works. On the LG when it needs to defrost it stops the compressor and fan, reverses the 4 way valve, starts the compressor only which now warms up the evaprorator, and only when it has warmed and melted all the ice, does it start the fan to blow the water vapour out. then it stops and swaps the valve back and returns to normal operation. I am always surprised how quick this happens, and if it happens quickly, it can't be removing much heat from the house. If yours is struggling to reach the demand temperature in the 20 minutes or so between defrosts, it sounds like it is working hard. Could the unit be under sized for the job?

I always board a ceiling first, then the walls, so the edge of the ceiling boards is covered by the wall boards.

Even an existing long standing discharge from a septic tank to a watercourse no longer meets the GBR and should have been upgraded to a treatment plant at least 2 years ago.

The screw screws into an expanding plastic fitting that is inserted from the top so it is a blind fitting. The screw and both the plastic fittings will need replacing, easy enough to buy replacements. The hardest part will be extracting the old one if the screw is just spinning. The tip above about applying upward pressure wile unscrewing the screw to get it to grip is a good one.

Yes we are. Many of us use wood burning stoves in an appropriate situation having assessed what harm it might or might not do and concluded in our case a very rural very low density populated and usually windy location, there really is not an issue so have chosen to use a WBS. I would not have made that choice if I lived in a more densely populated settlement in a windless valley where the smoke was likely to linger. But even when we make reasoned choices we are still told how bad we are and how irresponsible we are again and again and again by the same person. This whole environment thing is a case of each of us making the best choices we can in our individual circumstances. Few will be able to do everything possible, but just the best we can. And the "experts" don't help. If burning wood is "bad" then someone really ought to tell those running DRAX who keep telling us how carbon neutral and environmentally friendly it is. So prime example of even the environmentalists can't agree what is good or bad. No wonder a large percentage of the population is confused or frustrated by it all and many just can't be bothered because the message we are being given is too confusing and contradictory. All we should do on a forum like this is highlight pros and cons of different options and let the individual make their choices and don't keep slapping them down because their choice is not the same as yours.

There is more to boiler electrics usually than "plug it in" There are usually time clocks, thermostats, motorised valves etc and then it depends if it is a system boiler or combi. So get your electrician to look at the boiler first and see if he can move the electrics first and keep the boiler powered until moving day with some temporary cable(s) but even that may not help if the plumber is moving motorised valves and pumps etc.

There are only 2 heights relevant to building regulations. A domestic stair and landing, 900mm, and "everywhere else" 1100mm In a similar situation but only a 2 storey house, BC tried to tell me that "landing" only referred to 1 square metre at the top of the stair, and my galleried landing came under "anywhere else" and should be 1100mm high. Trouble was our chosen domestic handrail system was only available in 900mm high. A many week standoff ensued while our BC sought clarification and came back and said 900mm was okay. If you don't feel comfortable with 900mm then 1100mm is what you want, but it is likely to restrict your choice somewhat.

Surely even if no permit is needed (it is in Scotland, you won't say where you are) you would have required building regs approval for a new treatment plant? Have you asked the EA (or SEPA in Scotland)?

That's a big drainage area. Our previous house required 85 square metres and that was a 5 bedroom house with slow draining land. Have you started to look at alternatives like composting toilets?

The drainage field for our previous house and at least 2 others in this road, is under the field behind us, which is Arable land growing usually wheat or barley. So there does not appear to be an issue growing "food" on the land. The drainage field is quite deep deliberately to be well below the depth a plough would turn the soil.

Yes my Pi Music box seems to run for weeks on end without needing a re boot. What does still upset it is losing it's internet connection when streaming, if that happens too many times it just seems to lose the ability to re start streaming. But that is much better now we no longer use a lousy ADSL internet connection that was the best available when we got it, but frankly it was always a lousy unreliable service delivered over a copper cable network in such poor state is was a wonder it could actually handle a voice call.