Plumbing – Why does the pressure tank cycle so frequently

plumbingwaterwater tank

I have a 40 gallon (bladdered) pressure tank in the basement which keeps pressure to my office building, and a 2-inch 2 horsepower submersible pump in a dug well 450 feet away.

The pump is cycling waaay too fast, and the tank will hold pressure at 41 pounds to 43 pounds but not at 60 pounds at shut-off pressure. (The pump comes on at 40 and shuts off at 60). It only takes 6 seconds for the pump to come on and shut off and I fear I will cook the pump if this keeps up.

I have recently tested the pressure in the tank and it is 50 pounds. Does this mean the bladder leaked and caused pressure to increase in the tank? I know the tank pressure should be set at around 39, or a little below the 'turn-on' pressure. Could this be the cause of the short cycle?

Best Answer

The bladder is there to flatten the pressure/volume curve so pressure doesn't change rapidly as water is pumped.

This allows for a longer duty cycle.

The expected symptom of a burst bladder is just as you describe.