Said It Here

Why won't my well pump shut off when it reaches pressure?

When a well pump fails to shut off after reaching target pressure, trying to adjust the pressure switch usually doesn't fix the problem. The underlying cause is often a faulty check valve or a small suction line leak pulling air into the system. This prevents the system from stabilizing, leaving the pump running continuously.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Trying to adjust the pressure switch
  2. 2
    Isolating the system from the house by closing the valve past the tank
  3. 3
    Checking or replacing check valves
  4. 4
    Fixing leaks on the suction line

In their words

Unedited, most upvoted first, each linked to the thread it came from.

Had this happen on a new install. The check valve was the issue. Also had a small leak on the suction line sucking air into the system which led to issues.source ↗

PlanktonDisastrous74 · r/Plumbing · 1 upvotes

The pump will get to 50 psi but won't shut off. Trying to adjust the switch results in this.source ↗

Bananasugarnips · r/Plumbing

Where this came up

People with this problem also raised