I previously reported on my experience installing a pressure reducing valve on the main water inlet to our house. Well, it seems there's still some kind of problem. We've been noticing that one of our showers occasionally starts to drip water. I had thought that it was a bad seal in the show spigot (it's kind of a cheap fixture). Today it started dripping again and just on a hunch I went outside to check the pressure gauge that I installed on the main water line.
It read 130 PSI.
Holy shit! That's double what it should be, and 40 PSI higher than the maximum pressure that the pump is able to produce.
This is really bizarre. I have no idea how the pressure could have gotten up that high. The inlet pressure at the main is 30 PSI and the pump only pushes that up to 90. Somehow we're getting an extra 40 PSI from somewhere, and it's getting past the PRV, which is set to 65 PSI and is supposed to be good up to at least 150 PSI on the inlet.
The only thing I can think of is that we have an air bubble trapped somewhere in a hot water line. Maybe the air is heating up, expanding, and compressing the water in the pipes in the house. It seems pretty farfetched, but that the pump could suddenly produce twice the pressure that it normally (and that this would coincide with a failure of the PRV) seems pretty farfetched too.
As the King of Siam would say, is a puzzlement.
If anyone has any idea what might be going on here please let me know before my pipes burst.