We recently replaced an old boiler with a new Buderus oil fired boiler-----new t-stats,pumps,controls.
Customer calls today ---the t-stat is set for 65 and the room is up to 80+ degrees. Checked pumps --not running,contacts not stuck closed,boiler not running. Hummmmm--boss says its migration of water.
Anybody ever run into something like this????????
It is called a gravity system.(I think)
Install a zone valve or check valve.
I have opened the check valve on a system that had a bad circ. and none in stock. It would heat the house just fine.
Forgot to install the flo chek, left it turned open, or dirt got in it.