We are about to add radiators to our basement. I have bee told that
we may run into a problem because the radiators will be below the
boiler. First of all, is this true?

The way we are thinking of doing it is to have two trunk lines running
across the ceiling of the basement and branching off from there to the
radiators and back. The ceilings are 12 feet high. We will use
thermostatic radiator valves at each of the radiators (5 in all). The
rest of the house is control by one thermostat. Can anyone forsee any
problems?

I appreciate the help.