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Hello, so far it sounds like a failure to sense flame... since you have already cleaned the flame sensor rod, and since you have gotten a bogus error code from the printed circuit card.... the odds the flame sensing circuit inside the printed circuit card are high.
Tell me a lot about your technical skills in these sorts of areas so that I can coach you most effectivel.
and... tell me if you are able to identify the printed circuit card that the flame sensor wire plugs into or not.
We can go from there.
Possibly... its a matter of your preference regarding the risk of replacing the ignition module when the fault might lay elsewhere. There is about a 60% chance that replacing the ignition module will solve the problem
You could have a 'reverse polarity' problem at the power supply to the boiler... look this video over for how to detect and solve the problem.
most people need to see the video twice to comprehend that range of issues.
Reverse polarity damage is *cumulative in most cases, not causing sudden failure. see the video you will understand
Reverse polarity is an easy fix.
That question if best answered by the parts wholesaler who has a 6 foot long catalog on all that, as it updates monthly in most cases.
without that catalog answering that question would take 4 or 5 hours research and possible modifications to the rest of the system.