I bet the well pressure tank is full of air. All well tanks need a head of air to keep the pump from starting and stopping every time faucit is opened. on older systems there is a flapper valve that lets the standpipe to the submerged pump fill with air when the pump shuts off. when the pump starts the air in the line is forced into the well pressure tank. to maintain the proper head of air a float valve is mounted at the mid level inthe tank to let excess air out. If this float valve gets stuck, the tank will fill with air. you can check by opening a faucet by the well untell the pump starts and you should hear the float valve letting air out. if no air exits smack the valve with a mallat to see if you can dislodge the float.
If the tank has no float valve then its a diaphram type and it will not fill with air.
Dave and Laura & two cats
02 Discovery with Accord toad
retired auto rv tech and teacher, wife rt nurse