This may or may not help, but here goes. I had an intermittent problem with my CSI85T it would operate OK with the front control panel hinged down, but not firing up when the panel was put back up. Worked out by elimination it was worn out relays on the control board. Replaced the board which you can buy from Ravenheat Spares, problem solved. The control board differs from one model to the next, DO NOT believe the handbook for the boiler MINE WAS WRONG. Check the photo of the board and compare it to make sure the connectors match the one you have in your boiler.
CSI 85T control board, August 2010
