removing part of system

SRC

One branch of my steam radiator heating system goes to a metal air handle system that feeds a car like radiator device that a fan blows over to bring air into a large basement room. This car like radiator, like car radiators, has sprung a leak. It is very difficult to get too and thus has been shut off and not been used for nine years. The exit line off this radiator feeds some type of trap that then goes down to the floor and eventually under the floor back to the boiler room. Its the lowest return line back to the boiler. I was hoping since I no longer need this branch of the heating system I could remove that return line and thus be able to tile over the wood access panel in the basement laundry room where this return line passes through. Any issues with doing this???