I woke this morning the circulator on oil furnace was running but was not igniting. Shut switch off then back on same scenario. I then checked the coupling on oil pump to make sure was not broken, last furnace had that problem, checked nozzle was clean, put everything back together turn switch and then hit the contacts on aquastat relay and fired right up. Do you think aquastat type L8148A is my problem?
Or should I look elsewhere.

Is there a reset on the burner? If the circulator is running, it is because a zone is calling for heat. Try the reset on the BURNER ONCE. If that does not work... call a tech.

I had same problem yesterday morning. Started doing some trouble shooting, controller had no electric to it, went back to Aquastat it had 120V going in nothing coming out, removed and looked at circuit board had sign of solder failure on relay, got out solder gun hit with solder reinstalled and fired right up. Woke up this morning to a warm house. Thanks

l8148a is a cold start control disconnect T.T. 24volt termals jump out unit should run if it doesn't control is bad if it runs problem is in thermostat