Hello, I have one well that feeds both my home and detached above garage apartment. The apartment is not occupied at the moment so I do not want to pay to heat it. To prevent any pipes bursting I shut off the apartment's main water supply and then drained the building of all the water. Immediately after I noticed the water pressure in my home was pulsing full pressure to half pressure in consistent 5 second intervals. I turned the apartment water back on and refilled it, after which the pulsing stopped. As far as I know there is no link between the apartment and house water lines other than the main well they are both connected to. Does anyone have any ideas on what could be causing this?