dpmiller

searching the number on the PCB hints at it being a "world pac" unit. I'd be looking closely at the innards to confirm it's actually an inverter unit- should be another smallish pcb with a big heatsink and some big capacitors on, and there should be a 3-wire connection to the compressor, with no additional starting capacitor

auto bypass valve across the rads?

that's GB, not UK, generally...

yep, can't fault them. Connect wires, screw to wall, done. The're pretty slim on the wall. Haven't had any failures yet/ The USB ones seem to charge stuff ok. on the lightswitches, the actual switch can be removed from the faceplete by undoing a couple of tiny screws. This makes it handy if you need to have (say) an intermediate or an illuminated 20A switch in a double or 4-gang faceplate, or want one dimmer in the mix. Like a gridswitch kinda. 3-gangs are different as to cram the three into a single, the switches are in one housing...

adjusting the lockshields *must* alter the DT. After all, if they're closed enough there is *no* flow...

yep, I'd be reducing the pump speed a bit. Easy on the iVT-9

yep, it becomes obvious when you have a couple of panels to-hand where issues will occur. Look at my top row in the photo, there's a raised overlap between each panel and the side flashing sits over that again, that's a height of about 10-15mm that you need to squeeze in underneath whatever...

MK is common in government work. I'd tend to agree with @ProDave that they're a bit dear, and not the best ever quality. I went Hager for ours because they look clean and unfussy, and the lightswitches have a handy neutral terminal

better chance of it arriving in one piece if you collect from the local depot than expecting some courier to take care of it...

that's the valve at the "other" end of the radiator. It's used for isolating during repair, as well as setting the maximum flow- balancing- the system.

It's the DC component that's the issue, not the actual currrent and that could well be RCD brand specific. The original incoming 100mA type-S I installed in our meter box was sensitive to our CE-iVT9, as soon as the inverter was energised (but before actually driving the compressor to any degree) it would trip out.

if it's so easy why haven't you done it yourself?

those fixings have a degree of up-down adjustment and just clamp onto the round tubes, almost anything will fit...

we staggered ours. It meant taking a small slice off the side overlap joint and flashing of the "lower" panel, but the upper one covers it sufficiently and then the flashing roll was slid uo the back of it after tiling

what pump modulation are you seeing and what deltaT are you set to?

they don't know you from Adam, why should they trust you? You're just another trade and your mate is in it with you. Or so they likely think...

a wee circulating fan? PIV?

yes, my calculator works too... But as we've got DHW temps for some of the time, heating flow is 40c ish, and we're in a damp cool dip, I think an average COP of 3.6 sounds a bit too good to be true.

A full year of consumption records, as of today. Total consumption by the ASHP is 3232kWh and just over half of this is during cheap rate. Jeremy's calculator came up with 11700kWh annual heat requrement for an average year but I'm guessing the actual requirement is a fair bit less as our flow temps would suggest a lower COP...

being on the wrong side of the small pond massively kills choice, very few GB suppliers will ship. Bathline, Beggs, PTS. Plus there are a few smaller more merchant-y guys too. VP Jebb in Belfast, Stevensons in Bangor, there's another small wholesaler in Kilroot. I deliberately aimed low and ended up dealing well with Beggs, although I wouldn't darken their door normally for plumbing bits...

your local motor factors might help with replacements as many stock trailer parts.

can you program a slightly higher flow and room temp during the E7 period, to charge the house up? Whilst there's a small efficiency loss running during the lowest ambient temps of the early morning you're still going to gain over running at the day rate. That's what we're doing, and solar gain reduces daytime losses so there's actually very little heating needed during the day and evening

can your loft take the weight of either?

the clutch on that Hitachi will only be to stop it breaking your wrist, not for setting torques.

^ agreed. However spread of fire from an adjacent vehicle would be a different thing completely. EV batteries are darned-near hermetically sealed, generally have a heavy steel cladding, and most likely are full of cooling water. So getting an intact pack to light up will take a shedload of energy...