Residents are complaining of banging in the hot water baseboard heating system in our multi-residential building built in 1965. How difficult/involved is it to bleed the pipes? Does it have to be done in each of the living units or can it be done at a central location?? Does this require a licensed plumber or could a Council member do it? Should bleeding be done as annual maintenance?
Bleeding a water based central heating system is a DIY job anyone can do.
Find the bleed valves and crack each one open a bit (only one at a time though you don't want flooding). You should be hearing a hiss as air is pushed out. At some point water will get pushed out, careful it can be hot if the system is on, which is your sign to shut the valve again. If the hissing stops (no air is getting pushed out any more) then that means the systems needs more water.
Air will tend to collect at high points in the line. If there is any thought put into the system those areas will have bleed valves. Your best bet is to bleed from all of them regularly (once a year is fine).