I thought the tank just wasn’t getting pressure to fill back up but The psi reads 100 on the tank but no water coming out of faucets.
Assuming your pressure tank is a captive tank type (equipped with a diaphragm or bladder), are you referring to 100 psi shown on the pressure gauge you just replaced, normally located nearby to the pressure switch which is to indicate water pressure, or are you referring to the tank's air pre-charge pressure which is normally measured directly on the tank using an alternate gauge such as a tire pressure gauge?
We ended up replaced the pressure gauge. Water worked for a day and then no water the next day.
Assuming this pressure gauge is mounted directly beside the pressure switch, the nipple supplying pressure to both devices maybe plugged with sediment/rust, so the pressure switch is not sensing low pressure in the system and is therefore not activating the pump.
Replacing the pressure gauge may have temporarily dislodged some of the blockage, thereby allowing the PS to temporarily control the pump as intended.
Suggest 1st removing the PS & P Gauge to inspect the supply nipple and connections for blockage.