Hello - Maybe someone out there can shed some light on my problem. I recently had heat installed in my basement. It runs across the basement ceiling (above drywall) and behind sheetrock walls between studs. When the heat turns on you can hear a trickling of the water running through the pipes, then a fast banging sound - soon, the banging gets slower then eventually stops. The banging sound only seems to be behind the wall. Any suggestions?

Bleed the air out of the system. Then make sure your system is set at the correct pressure.

((I recently had heat installed in my basement))

The company that did this work should have installed bleeders and bled the system for you. You might call them back and have it fixed like it should be.