Our sink, shower, etc work fine for a few minutes. Then the pressure drops to Zero. After a few minutes without water the water returns and works properly (this cycle then repeats). I went to the basement a noticed the tank is not refilling until the pressure is zero (I quickly pressed the air release value on the tank and it has pressure). It seems that the pump is not turning on at the correct time. What is causing the pump to delay turning on?

Thanks