2 of my hot water radiators have no bleeder valve installed. I have 2 new ones that I wouldlike to install, and everytime my plumber is here, he finds a way to not have time to install them. I have never tapped anything (other then those aluminum kegs), but am very handy. Should I buy the tools and do it myself, or have a plumber do it?

I have a heating contractor coming tomorrow for an estimate on changing from oil to natural gas hot water boiler. I did the heat loss myself since I am more familiar with my homes construction and insulation values since I have been here for 20 years. This is what I have. 63 year old New England cape 1950 sq ft on 2 floors. Upstairs is new with insulation to code 2 beds 13 x 22 with a full bath. Down has 1 bed, dining, kitchen, bath, LR and 320SF new family room above unheated crawl space. Main house is above a finished but normally unheated basement. Upper level came in at 12,439 and the lower 31,951 for a home total of [B]44,390[/B]. The design temps were 9f and 70f. System temp 180. Does this sound right? Seems low.