Gas Vent Damper Question

Hi Guys, newbie here. I have a Field Control GVD-6, installed in 2008, which is sticking when opening. Its installed on a Utica PEG-B Gas Boiler. This morning I heard it ticking and opened it manually. Immediately the boiler lit and the heat turned on. The sticking has been happening throughout the day. I thought that I could flip the service switch on the damper to hold it open but when I do this the boiler will not turn on. I have tried turning the switch to hold open when the boiler kicks off but before the damper starts to close. Also tried while the boiler was running (boiler immediately turns off). Finally I tried it while the boiler was off, then manually opened the damper. Regardless of how I do it the boiler will not light once the damper is set to hold open. Am I doing something wrong? Might it have been wired wrong when it was installed? I did not install it. Any help would be appreciated.
The system uses a Honeywell L6006A Aquastat and has an intermittent pilot.

Gas Vent Damper Question