Vertical pressure tank connected to a water pump outdoors

Replace and install a well pump pressure switch

The pressure switch on the tank tee turns the well pump on at cut-in pressure and off at cut-out. Replacing it means killing the pump circuit, draining pressure, swapping the switch on its sensing nipple and wiring it exactly like the old one (line from the panel, load to the pump). Confirm the tank precharge afterwards, because a bad tank often gets blamed on the switch.

Cross-checked ~60 min moderateBrands: All

Before you start

Most well pumps run on 240 V: turn off the breaker, lock or tag it, and verify dead at the switch terminals with a meter before touching wires.
Drain all pressure before unthreading the switch.
Work on the pump circuit itself, a new disconnect or a breaker change is for a qualified electrician where required by local code.

Diagnostic steps

Unlock all 10 steps with expected values

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