On Mar 3, 10:15 pm, "Bob S." wrote:
On Mar 3, 9:51 pm, "Harry K" wrote:

Except that isn't his problem. He has changed the pre-charge
correctly witht the tank empty so there is plenty of air in it.

Sorry, you're right. I read too fast and missed the "when empty"
part.
Bob S.

Wait, maybe I apologized too fast. How does he know the tank is empty?
If the tank is waterlogged from a split in the bladder, the water
between the tank wall & bladder wouldn't drain off. There would still
be air at the top of the tank to give a pressure reading, but pressure
switch operation would be very squirrley. That's what happened to
mine, but I had the additional clue of rusty water when it sat
overnight. I still think it is a "possibility".