I am removing my old boiler system for a new gas furnace. However, the HVAC crew will not be removing my old boiler system. How can I drain the water out of the old system so that I can remove the radiators? The boiler is located in the basement, and there are radiators in the basement level as well. The radiators look to be little more than copper pipes with fins, no valves (that I have seen) or anything. My main question, is how do I get the water out of the pipes that run under the basement floor without making a huge mess? Thanks!