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That's because they aren't floating, there's an X2 capacitor across the transformer to act as an RF return path for the switching noise that's coupled across the interwinding capacitance of the transformer. It'll naturally float at around half the mains AC voltage and will allow somewhere...

Exactly, the heat loss on these cylinders is minimal, so over the course of a day where you are out for a few hours the savings are minimal. I don't think anyone is disputing savings from weeks of no use, but a time clock is no use for that anyway.

The Honeywell CM707s are pretty good and reliable. What do you hope to achieve by replacing with Nest?

There will likely only be minimal savings by doing so since there is always heat loss from the cylinder until it matches room temperature. If you leave it off until just before you get back, you still need to replace that lost energy.

Actually I had it slightly incorrect, the risk is higher with freshwater, since you apparently only need a voltage gradient of 6V/m to result in electric shock drowning. It's much more difficult to get that kind of gradient in salt water since it has a much lower impedance. The usual effect is...

Once in proximity to sea water, all bets are off. Remember we're just a bag of salty water and other bits, which has a low impedance. The skin is high enough impedance that we are generally protected from ELV electric shock, but if you are in sea water that no longer applies.

It's saying test at 500VDC unless damage is likely, in which case it is acceptable to test at a lower voltage so long as it meets the alternate requirement for insulation resistance

Every house having an SPD will not have any perceivable effect on surges which appear on the LV ring. Everyone seems to forget transients are high frequency events exacerbated by the parasitics of each LV drop to the house. Think of it more like an impedance matching problem.

That's not strictly true - It depends on the energy in the surge. MOVs will happily repeatedly dissipate surges within their repetitive surge rating. The MOVs in most pieces of equipment are happily dealing with transients all day long, it's only when something more serious happens where there...

You will get a low IR reading if testing at 500V with surge protected leads in place, but not at 250V. Why was he testing IR with everything connected?

Surge protectors have MOVs between all poles. Don't confuse them with EMI filters.

The "simple, cheap version" is identical in parts that are in a CU based SPD - Simply MOVs and a gas discharge tube. The gas discharge tube is pointless in an extension lead since the inductance of the lead is too great for it to be useful.

That's completely untrue. How did you arrive at that opinion?

It won't be anywhere near 200 lm/W, probably struggling to reach 100 lm/W since the LEDs rated for high efficiency are not achieving this with high flux LEDs being driven at the maximum output! If you look at the published data they get this number from the highest binned LED being driven at a...

It doesn't. Electricity is primarily priced higher because of environmental levies. Essentially as a move to get people to use gas heating instead of electric fan heaters etc. We'll likely see gas prices rise soon as a means to push the heat pump agenda.

Not in the case of a system where the meter is remote from the cut-out. This is the responsibility of the property owner.

V-Pro dimmers say 10x lamps maximum regardless or type or power draw. Try removing a few lamps and see if you get the same results.

Does your consumer unit already have RCD protection? You may be complicating matters by trying to use plug-in RCDs

Definitely need to hear JW on the Hammond

Some IKEA lights don't work when the maximum load is exceeded. One of the pendants I bought just had a PTC in the lamp base to stop you putting in a higher power lamp.