Periodic Oil Burner Trip but Fires Up Fine

[Brianosaur]

The Beckett Burner on my Peerless Boiler was/is intermittently tripping. It began a few months ago and tripped about every 10 - 14 days. When I would reset the primary control it would fire right back up. No puff, no smoke, no dripping. It will run until the it heats up enough hot water and then stops firing on its own. It fires up as if I had just manually shut it down and then simply restarted it.

I hadn't changed the nozzle or filter in a year so I thought clogging had been the issue. After a month with a few resets happening every 7 days, I finally got around to putting on a new nozzle, changing the filter and brushing & vac out the boiler.

When I was done, as usual it fired up normally and it had been operating fine for a few days. However, it just tripped TWICE TODAY. Fired up fine both times.

In my 17 years in my house. I have replaced the following:

CAD 15yrs ago
Transformer 12 yrs?
Primary Controller about 10 yrs?
Oil pump (and checked/set pressure) 5 yrs
Delay Solenoid valve 5 yrs
Electrodes prob every few years
Combustion chamber liner changed last year

I replaced the CAD about 15 yrs ago but I pulled and tested it with an ohm meter. Zero resistance with a light bulb shining on it and slowly maxed out when covered up.

I'm thinking primary controller is malfunctioning but would it go bad in 10 years?

I'm sure there is probably a whole host of *possible* causes, but any help for what would possible be the issue would be appreciated.

Thanks