"shibumi" wrote in message oups.com...
Hi Folks,

I'm not sure if I have a pvc leak somewhere, or a well problem. The
symptoms are loss of pressure, heads that will pop up and down, then
spray, then lose pressure and pop up and down again...

This happens in 3 of the 6 zones. The other 3 zones run great.

In 2 of the zones we can hear a loud 'knocking' or 'surging' of water /
air when the pressure drops... You can even feel it "thumping" in
certain parts of the yard... we tried doing some random digging where
we heard the knocking and felt the 'thump thump thump' as the surge was
happening - found the pvc - but after about 6 feet in length of digging
1.5 feet down, (and finding no wet spots) we figured there HAS to be a
better way than just digging up the yard.

First - does this even sound like a leak? Could a leak in one zone be
affecting other zones? Why would the 'thumping' be louder when it gets
to zone 3 - as opposed to zones 1 and 2 (no thumping, but definitely
surging / changing pressure).

We haven't found any noticible 'wet spots' in the yard to indicate a
leak - even when we dug in the spots that had the most thumping, the
ground was dry..

Any ideas on how to easily find a leak? And again - does this even
sound like a pvc leak?

If your water pressure is on the low side, it could be automatic drain valves, which
close under sufficient pressure, opening due to dropping pressure as the tank pressure
drops. Do you notice the symptoms coincide with the pump cycleing?

Bob