what am i missing

5pencer

been trying to get my heater to work for the past month, called a service guy out and he couldn't get it to work I have replaced almost everything and still no success, at first it started with the boiler would kick on, ignite than turn off after a second of running, so I was told to replace the flame rod sensor, now it wont kick on at all and was told to replace to control board, replaced that and still no heat.

Ironman

That's mighty slim info. It's kinda like saying "my car won't start, so I replaced the battery and it still won't".

Make and model of boiler, any ancillary controls, etc. Pics of the boiler and controls would help.

Proper trouble shooting is done with instruments and a good DMM by a tech who knows how to use them. We'll try to help if you provide enough info, but without someone on site who can provide the needed readings, it's a guessing game, not a diagnosis.

One simple thing that you can check is the grounding path. It has to be solid from the boiler all the way back to the electric panel for the board to "see" there's a flame.

ratio

I think you'd be better off replacing the tech before you replace any more parts.