chuckclaunch wrote: Not 100% sure what this does... seems like a group temperature sensor set up in some kind of epoxy? Any maintenance I should do here while it's easy to get to?
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The piece in your hand is the sensor for the flowmeter. There's a pair of magnets on a little merry-go-round in the little roundhouse upon which that sits.
If it's working, no maintenance needed. And now you know where the flowmeter is.

Looks like you did a great job!