A couple of times lately I have been in the shower on the second
floor, and the water pressure dropped to the point where the gizmo
which diverts water from the tub faucet to the shower head dropped by
itself. My pulling it back up again and holding it up resulted in no
more than a trickle of water out of the showerhead and the faucet. I
think this happened when my spouse flushed a toilet in the basement.
Flushing in the basement also causes a dramatic reduction in flow at
the second floor sink faucet.
Also, during the backwash part of the cycle on the water softener
system, water availability is much reduced.
Our house is 25 years old, we have lived here for 15 years. We have a
private well. The gauge on the expansion tank reads 40psi (with no
water flow anywhere except maybe the reverse osmosis drinking water
system.) These problems appeared at approximately the same time as
the addition of the RO filter, but perhaps that is just coincidence.
I would love to understand what is going on.