Flue collector removal

newhouse34

Trying to remove flue collector to access baffles and I’m at a standstill with single digit temps in ny.. Utica boiler usc4lp.. I removed two side bolts holding it to boiler castings and removed caulk from back and the sides. The box will start lifting up from the back but it seems to be anchored some how on the front so it won’t come off. I’m afraid to force it and break something since it’s my first time with this boiler.. is there something I’m missing or a trick to getting it off ?

newhouse34

Here’s a pic

SuperTech

Gas boilers like that are not meant to be opened up like that, what are you attempting and why?

newhouse34

It says in the manual to do this annually to clean the baffles