ProDave

Incoming water temperature makes no difference. It is a fixed heater element that is always on, it does not adjust the power. If the incoming water is colder you will have to turn the temperature dial up, which will reduce the water flow rate to achieve the output temperature you want. Most people don't realise that in the majority of electric showers the temperature know bust adjusts the flow rate of the water through the shower. It could be the rcd function tripping it, that's the trouble with rcbo's, if it trips you don't know if it was over current or earth leakage. It was probably a 7kW shower installed originally. You could just change your 8.5kW shower for a 7kW but you would get even less hot water out of it.

In a perfect world yes. Depends on the reference method, but if it has been working without issue for a number of years with a cartridge fuse, then the cable is probably not going to come to harm. I would start by measuring the actual current drawn in use.

So it is losing pressure but nobody has bothered to try finding the leak?

8.5kW at 230V is 37 amps. It will be the over current function that is tripping, not the RCD function. Replace it with a 40A rcbo.

The regs are different in Scotland, they were not needed in each bedroom just on a landing and within 3M of a kitchen door. I put a couple of extras. Utility room, I want to know if the tumble dryer is smouldering. Plant room / workshop above the garage, it is so far from other rooms I want to know if anything is going on in there. Kitchen /diner was just covered by the one heat alarm. Aico do a heat and CO alarm all in the one package that made things neat in the kitchen diner (gas hob and WBS so needed CO)

AICO without a doubt. And definitely NOT Fire Angel.

It will have a generation meter. So take the reading from that and divide by 12 and that will be the average per year. I hope you managed to transfer the remainder of the FIT contract when you bought it. That would have been a 25 year FIT contract so another 13 years to go and probably something well over £1000 per year. It's will currently be paying over 60p per kWh generated

Before doing much more, I would wait and see if the little bit you have done appears to dry up. i.e. have you really found the problem?

Not that sort, but I have owned and used a "3 way ladder" for years. It has been solid, stable, dependable and very versatile. Several people have told me how unsafe they are, but I disagree. Something similar, but not identical to this one. https://www.screwfix.com/p/mac-allister-2-section-3-way-aluminium-combination-ladder-2-6m/4165x

Depends on the buyer. When selling ours, nothing was mentioned about the solar PV even though the buyer knew it was there. Only now, AFTER the sale is compete am I helping the buyer take over the remainder of the feed in tariff contract.

Or an offset set part on the landing part on the top flight. You might want an assistant to hold them if you are not steady on a ladder.

Can you not get the supply to plot 2 laid in at the same time, but leave the supply head unterminated with no supplier appointed and no meter, hence no council tax trigger?

Probably the opposite "Oh a combi great idea, no hot water tank, plenty of hot water on demand" Until the reality kicks in "Hot water takes ages to reach the tap, furn it down and it gets too hot to hold your hand under, go for a shower and the flow rate is pathetic and it goes either stone cold or scalding hot if someone in the house uses another tap or flushes a loo"

What are your plans? Develop both plots yourself? Sell the plots? build on one sell the other etc? It is clearly best to get services connected to both plots together, and it can take a long time, so I would start now and if you do sell them, they could be sold as serviced plots. What about drainage?

No 1 question is where is the leak and was it fixed? No 2 question is the expansion vessel okay and was it checked. The 2 are very probably related.

So time for a "finished" couple of pictures. First the outside finished and with all trimmings. The whole design idea of the slim door framing with the door opening going right to the corners worked well. Framing a bifold door with a track across the top is a lot harder to get right than an ordinary door. I started with the door track fixed direct to the 3 by 2 framing, i.e. not a finished surface. I then fixed 12mm Oak trimmings either side of the door track to give the finished surface to the top of the door frame, effectively making the track recessed into the door liner. Otherwise just fitting the door track to the finished surface of a normal door liner would have looked horrible. The slim moulded Oak profiles to finish off the edges worked well as conventional architrave would not work with this door right to the corner idea. Then there was the shelving for the inside of the short wall. I was looking for some shallow shelving for tins, jars etc. We ended up with this. This is shelving units quite cheap from Temu. They do them as solid flat shelves or baskets. The flat shelf ones work best being exactly 2 tins deep and 4 tins wide each. 2 more are on order so when they arrive, this will be re jigged to give virtually floor to ceiling shelving with the baskets at the bottom and the solid shelving ones higher up.

It is compounded by the fact that with an UVC everything should go through the pressure reducing valve and all cold taps fed from that for balanced pressure. We feed the kitchen tap directly not through that but still regard the pressure reduced water in the bathrooms as potable.

I am not sure I would want my drinking water passing through (and sitting for some time in) a radiator not designed for potable water. However, if I had planned ahead, it would have been very easy to make the cold feed to the HW tank (which is above the pantry) pass though such a radiator. Or the cold feed to the WC flush tanks.

The simple solution is for one of the automation / smart switch providers to make a smart switch with changeover contacts aka an intermediate light switch. Then you could wire conventional light switches, any number of them in each room, AND a smart switch that would all work together. And if the smart switch died, it could easily be bypassed leaving just the conventional switches until you could fix the problem.

When we built the house, the pantry was always intended, so that corner of the kitchen and the place where the fridge sits, does not have UFH under it. Now it is finished, the pantry does seem to remain cooler, subjectively. But I suspect that is more a case of when we light the stove in the evening as long as the door is kept shut, the pantry does not warm up like the rest of the ground floor of the house. I must put the min / max thermometer in there to see.

The very last place I want my phone at night is by my bed. It gets plugged in to charge overnight in a different room.

And that could have been solved 10 years ago at a pen stroke by a change to both planning rules and building regulations. Think how many thousands of houses are still being built that fall a long way short of passive house standards and will take their turn in the upgrade queue eventually.

So delete the G3 course and add the £1500 to pay a plumber and electrician and that is still a sub £5K install, so should be entirely covered by the BUS grant. If only.

I say it needs instructions. Pester them for the instructions. While some of it might be obvious there are for instance 2 identical 3 pin connectors on the new board. It may or may not matter if they are connected the wrong way, but I would prefer to know rather than hope.

If the room heat loss is 1800W and this unit is rated at 1680W at 50C water but you are going to feed it with 40C water at an estimated derating of 50% then it won't have enough heat output for that room.