Need a little assistance here. I have a 30 gallon pressure tank(I think) a submersible pump and the switch is set to 20/40. I got the pressure in tank to 18#.

The problem is when the pump shuts off and the water is still running, the pressure will slowly drop to about 20, then suddenly drop to 0 and the faucets stop. After 30 seconds the pump will turn back on and return pressure to 40# and turn off.

I've noticed that it mostly happens when using one particular bathtub. I'll double check the system by using other faucets in the house, but I don't understand how a particular tub would be the problem. Unless its some sort of low pressure cut off. I thought it was the pressure switch so I changed the pressure switch today, and everything was working fine until once again using that bathtub.

I'll have to check the new switch to make sure its still doing its job and didnt fry due to some electrical issue. Could possibly be related to lightning here too. Lightnight hit nearby and I saw a spark jump in between the washer and dryer. This was a while ago, about 2 months, and at the time I didn't notice any problems with the water.

I've been at this for days. Any help would be greatly appreciated.

Thanks,
Brandon