Hi All - I was looking at my in-law's Viessman boiler installation, and something struck me as not right about it. It's plumbed for 4 zones and a DHW tank. It looks like this:
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What doesn't look right to me is the left-most circulator. Is it installed backwards? Shouldn't it be pulling from the expansion tank, which is plumbed on the supply side of the primary loop?
What doesn't look right to me is the left-most circulator. Is it installed backwards? Shouldn't it be pulling from the expansion tank, which is plumbed on the supply side of the primary loop?