Trying to get my head around this system in our cafe. It's the relationship between the circulating pump and the ?bypass (above the red knob on the right) that is not making sense to me.
It just seems like the circulating pump is dragging the cold water around and around through the loops. It's doesn't look like other manifolds I've googled...
What you have there is a standard manifold, plus a temperature-controlled recirculating pump (which is not the main pump!) and a hot-to-cold bypass line.
Try closing the bypass valve. The picture isn't too good, but I assume those are all temperature gauges, so the only warm water flows through the bypass at the moment.
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.
Realistically, at this point you call s professional and get it checked out and explained to you.
I've tried. We're rural and tradies just don't want to know.