If a well system is losing pressure, cycling rapidly or spitting air, the fault is more often the pressure tank than the pump. That is the useful thing to know before calling anyone, because a waterlogged pressure tank makes a perfectly healthy pump behave like a failing one — and replacing a pump that did not need replacing is an expensive way to fix a tank problem. Rapid on-off cycling in particular is the classic signature of a tank that has lost its air charge, not of a worn pump.
What the pressure tank actually does
It is not storage in the way people assume. The tank holds water under pressure against a cushion of air, so that when you open a tap the tank delivers the first volume rather than the pump starting every single time.
Without that cushion, the pump starts and stops on every small draw. That is called short cycling, and it is what destroys pumps — motors fail from starting, not from running.
So a failed tank does not merely cause symptoms. Left alone, it goes on to cause the expensive failure people were worried about in the first place.
Symptoms, and what each usually points at
Rapid cycling — pump kicking on and off every few seconds during use. Almost always the pressure tank. The air charge has gone, or the internal bladder has failed, so there is nothing to cushion the draw.
Pressure fluctuating while a tap runs. Also usually the tank, for the same reason.
Air spitting from taps. Air is entering the system — a failed bladder, a leak on the suction side, or the water level in the well dropping to where the pump is drawing air.
Pump running continuously and never building pressure. This one does point at the pump, or at a leak somewhere in the system large enough that pressure never reaches cut-out. Worth acting on quickly — a pump running continuously is a pump wearing out.
Sediment appearing in the water. Can indicate a failing well screen, a dropping water level, or a deteriorating component.
Moisture around the tank base. A corroded tank. That is a replacement, and it is better caught before it fails properly.
Why catching it early matters
A corroded, leaking pressure tank is a straightforward swap. The same fault left alone leads to short cycling, premature pump failure, inconsistent pressure and a considerably more expensive repair — because now you are replacing the tank and the pump, and pump work means pulling the pump.
That is the argument for treating pressure symptoms as worth a look rather than something to live with.
Sizing: why a 52-gallon tank is common
Tank size determines how much water is delivered between pump starts. Too small, and the pump cycles more often than it should even when everything is working.
A 52-gallon tank is a solid size for a typical residential well system — enough drawdown that the pump runs in reasonable cycles rather than pulsing. The right size for a given property depends on the pump's flow rate and how the household actually draws water.
Well systems are their own world
If you have moved from a city supply to a well, the mental model changes. There is no utility maintaining anything past the meter, because there is no meter. Pressure, flow and water quality are all yours.
The practical version: pay attention to changes. Pressure that feels different, a pump you can hear running more than it used to, moisture where there was none. On city water those things are somebody else's problem. On a well they are early warnings, and they are much cheaper to act on early.
Related reading
Frequently asked questions
How do I know if my pressure tank has lost its air charge? Rapid short cycling during use is the clearest sign. A tank that feels uniformly heavy and full when tapped, rather than hollow in the upper section, is another indication.
Can a pressure tank be recharged rather than replaced? Sometimes, if the bladder is intact and the tank has simply lost air. If the bladder has failed or the shell is corroding, it is a replacement.
Why does my well pump run constantly? Either the pump can no longer build pressure to cut-out, or something is bleeding pressure away — a leak, a failed check valve, or a stuck pressure switch. Continuous running is the symptom worth acting on soonest.
Does a well need a permit for repairs in Sonoma County? Well and septic work falls under Permit Sonoma in unincorporated areas, and requirements depend on the scope. A pressure tank swap is a different matter from work on the well itself.