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Backflow preventer leak

617 Views 1 Reply 2 Participants Last post by  surferdude2
My boiler has a backflow preventer that is dripping pretty steadily from the downpipe.

I think I can manage a replacement, but just wanted to make sure I'm looking at the right part and that this is in fact the correct course of action, replacing this backflow preventer.

Is this a suitable replacement part?

And am I right in assuming this is a wrench job? I don't mind sweating pipes but it looks like I can maybe keep the existing threaded connections.

Side note: The leak started after I had to shut off the main supply to the house briefly. There was no leak before the shut-off, and after the water was turned back on, the backflow preventer was leaking. Why would a temporary shut-off of the main water supply trigger this leak?
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You might be able to fix that by soaking it in CLR for an hour or so (longer if you can). It likely dislodged some lime or calcium scale when the plunger opened the vent when the pressure went off that normally holds it shut.

The Watts unit looks like a good choice if you must replace it. May have different nut size or thread pitch so sweating it in may be required.
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