ProDave

Yes wire it as shown, all detailed for you.

I take it the wooden ramp was accepted. Duly noted in case we have issues.

Connect the iboost to the bottom immersion heater Connect the ASHP immersion control output to the top immersion heater. The cylinder thermostat plays no part in the immersion heaters, It probably pays no part in the normal control of DHW from the ASHP. That usually has a temperature probe for that. But the cylinder thermostat must be wired as a safety device to shut the motorised valve to the cylinder if it is triggered. It will normally never do that, but is there to stop the cylinder overheating if other systems have failed,

You would do very well indeed to build that for a total of £200K (£1K per square metre) Probably £300K is a more realistic total build cost. You don't hint how much you are expecting to do yourself? All in turn key and a total bill of £400K would not surprise me. I would say 60-70% of the cost is in getting a complete shell.

We bought one,. First year it worked well, the leaves fell down quickly in a sharp frost and they blew into nice piles easily. Next year, the leaves fell down gradually in a prolonged wet and windy spell. The leaves were stuck to the ground with water and the blower would not shift them and they never dried all winter enough for the blower to shift them. We used the rake.

We used a digger with a lifting boom attachment

I still do not see anything in the picture of the CU posted to suggest this originated via the mains supply. So in the absence of any explosive issues within the CU I dount a plastic one would have faired any worse.

What I am trying to understand is how the high voltage got onto the phone line. i.e. does the phone line originate as an overhead on the same pole? If it is underground and totally away from the electric I can't understand how it happened.

First there is nothing fundamentally wrong with GRP as a technology (I say speaking as someone who sails in a 50 year old GRP sail boat) The problem you have is poor workmanship. You need the contractor (the person you appointed to do the job) to sort it out. I hope you have not paid in full for the work yet, as if not you have a lever to make them put it right, and make sure you watch what they do to "put it right"

I did some back of envelope calculations. My roof windows are small. the difference in heat loss between 2G and 3G, and the difference in cost between 2G and 3G meant the saving in heat loss would never repay the extra cost of 3G.

The description of this puzzles me. How could a buzzard flying into the transformer cause this? The only concevable way is if it bridged between the 10kV incomet and 240V outgoing. But I would expect the buzzard to be severely charred and all the house electrics to have flashovers at multiple points and just about anything electronic blown. Does the BT come in above or below ground? I take it the BT line is toast and OR need to repair it? It sounds to me more like there was somehow high voltage on the BT line and the fact you happened to find a dead buzzard outside just after was coincidence?

The UFH circulating pump only turns on when one or more zones is calling for heat. There will be a short period when it turns on before the actuators have opened (hot wax actuators take a minute or 2 to open) when it will be pumping into a dead end but it does not seem to bother the pump.

Check with an ohm meter the the switch contact closes when you activate the switch. It could be as simple as a dud switch.

So, technically, YOUR car was NOT insured. You had in fact insured a different car that you did not own. The fact you are not on a charge shows the police have accepted it as a gernuine mistake and providing you now correct the insurance it should be the end of the matter. Why do I get the feeling that had the car been stolen, if the insurance had spotted the mistake, they would refuse to pay out because your car was uninsured?

Yes it was agreed for an unvented cylinder fed with treated mains water there was no legionairs risk, but you cannot say that for a vented tank fed cylinder so it would be wise to regularly heat it to 60 degees or more.