Draining & Filling Boilers

I really want to save some money with the install of my wood boiler to my oil boiler. I have plenty of plumbing experience (sweating pipe, etc) so I'm running all the copper between the two boilers, hooking up the new circulator, and a few other odds and ends. However, since I have NO experience with draining and filling a boiler, I wanted a plumber to make the tie-in's to my existing boiler for me and have him drain/fill/bleed the system. After all - we're still in the middle of winter and I have a wife and baby in the house....

With that said... I'm still thinking about making the tie-in's myself since it will save me about $400 bucks and looks easy to me. Adding the Tee's (tie-in's) to the existing piping is a no-brainer for me but how difficult is it to fill and bleed the system when I'm done?? Do I just open the air vent over the expansion tank???? Should I open the pressure blow off valve and maybe even the check valves too?? My worse fear is getting it all back together and getting air locked or something that prevents the system from re-heating the home!

Any advice will be greatly appreciated. I've provided some pictures below so you can get a better idea of what I'm working with.

Burnham Boiler / Becket Burner

Drained the boiler, added the tie-ins for the new wood boiler, and filled it back up. It was cake! I even added a drain valve since there was non, a purge valve, larger expansion tank, and zone shutoff valves. Previously, there were only shutoff valves on the return of the zones, just above the circulators.

I have a question about boiler pressure. Before I started the work, I noted the pressure was 30psi which is what the boiler has been operating at since I've owned the home (6 months). The boiler manual says to fill the boiler until 12psi and then it goes right into saying not to exceed the maximum psi as noted on the boiler nameplate. The boiler nameplate reads 50psi max. So I ended up filling it initially to 12psi as stated, purged the system, and then continued to fill it back to 30psi. After about 12 hours of operation, the boiler is still operating at 30psi so it's running normally. However, forgive the noob question - since the max is 50psi, should I increase psi higher than 30psi? Will there be any performance increase if I increase the operating psi?

Take a look at the pics:

Boiler Pressure - Burnham V8 model W83 installed in 2006:


BEFORE



AFTER


Pipe with 3-speed circulator sending return water wood boiler return (wood boiler located in garage)



Supply with check valve from wood boiler. Also note the purge valve.


New drain valve. I had to stick a wet-vac hose down the 1-1/2" return pipe to drain the boiler since this valve was not previously installed.