knight won't fire

Inside the cover, down to the lower left, there is a white PVC cyclindrical device. THis is the condensate trap. It has a float switch inside of it that if the drain outlet plugs up, will cause this condition. You should check the drain, possibly even taking a wet vac and attaching it to the drain to make certain it is completely clear. If that doesn't work, call in the installers to have them check it out.

ME