Boiler keep going past the Aquastat High Set point 180F.

Hello, I have an oil boiler with baseboard hot water and four heating zones system. Recently, I have three technicians from same company to come to fix the boiler related problems. The first technician was called to replace a leaking mixing valve and he also did a tune up. Several days later, I found some water come out from the pressure relief valve. The second technician was called to investigate, he realized the first one set the Triple Aquastat L8124A,C high at 220, and he dialed it back to set High at 180, Low at 160, Diff at 10. But I still get water from pressure relief valve, the third technician was called in and now he thinks the Aquastat is not working correctly.. Because even with adjusted setting, the temperature/pressure gauge measuring the boiler water read the temperature as high as 210F and pressure as high as 30psi. The pressure will go down quickly if I run hot water. Once the boiler is on, it dosen’t stop at 180F, instead it stops at around 210F. Do you agree with his conclusion? Could it be that when the second technician dial back the set point to 180, he never let the water temperature went below 180F and messed up the Aquastat? Would it help if I turn off the boiler and let the water temperature go below 180 and then turn it back on? Thank you in advance for your advice. Cindy