Vertical pressure tank connected to a water pump outdoors

Well pressure tank annual check: precharge, switch settings and cycle time

A bladder or diaphragm well tank holds an air charge that should sit about 2 psi below the pressure switch cut-in (for example 28 psi on a 30/50 switch, 38 psi on a 40/60). The charge can only be read with the pump off and the system drained to zero water pressure. A yearly check catches a slowly leaking charge before it short-cycles the pump. Water from the air valve means a failed bladder.

Cross-checked ~30 min moderateBrands: Amtrol, Flexcon, Well-X-Trol, All

Before you start

Turn off the well pump breaker before draining; a pump running against an empty tank can be damaged and the pressure switch terminals are 240 V on many systems
Do not adjust the pressure switch with the cover off and power on

Diagnostic steps

Unlock all 6 steps with expected values

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