If the boiler is giving you a 'lockout' error and resetting it doesn't make things better, the most likely problem is that the air intake is blocked by a snow pancake. The solution is to go outside through the door at the bottom of the stairs--being careful not to lock yourself out--and find the intake tube.
See the one that points down? No? Here, look closer:
Reach up under that downward-curved tube and pull out the little snow pancake. If you can see the metal grate, go back inside and hit the reset button again.