Help. Everytime it rains I lose TV channels from the 120's through the 150's on my fios service, along with my internet service. I've changed the outside 3 way splitter more than once. I've even tried putting the splitter inside of a plastic outlet box to keep moisture out the connection. Same problem. Does this seem like some kind of break in the coax somewhere, or a bad connector where water gets in and causes a short?? Sounds like I might need a truck roll..
Sounds like a ground fault or a short somewhere.
Before a truck roll, I would suggest you test disconnecting the 3-way splitter and running a direct piece of coax (across the floor and thru the house) from the ONT to your router and/or STB. If things work ... then the problem is with the wiring inside your house and while Verizon would do a truck roll to fix it -- they will also charge you. You'd probably be better off contracting privately or doing the cable replacements yourself.
If it fails when directly connected to the ONT with everything else disconnected, then it's something with the ONT that's bad and that would warrant a truck roll for replacement. Don't think it would be anything further upstream or else all your neighbors would be complaining as well.