Oh no, won't someone think of all those critical Temu shipments! Anyway...
(Seriously, there must be a lot of irreplaceable stuff that goes through the post - this is actually a fairly big deal and I'm sure there will be people quite badly affected. Horrible to think about actually)
Yes, there's another pump back in the main line from the boiler.
With the bypass valve closed, the hot water doesn't seem to circulate at all - either down the bypass or through the loops.
And, the thermostat on the circulating pump there switches it off below whatever temp you set. Once switched off, then the top rail starts to heat (implying that got water is now going into the loops). So strange , I just can't get my head around how it's 'supposed' to work, let alone if it's actually working properly.
I sang semi-professionally for quite a few years. Used to use in-ear monitors and they do a similar thing - you do get used to it pretty quickly, or at least it becomes less annoying!
Thanks @dave, yes indeed - pretty unique GlowWorm adventures out of Charleston on the West Coast. Drop us a line :)
And yes, have been quite absent of late! Still lurking every now and then but spare time is a distant memory lol