Performed a heating pm on an oil boiler. Brushed and vacuumed. Replaced the oil filter, nozzle and strainer. Started and checked the safeties. Performed a combustion test. System is operating properly The pressure relief valve has a slow drip. The pressure/ temperature gauge is reading 25 psi. The temperature side of the gauge is broken. Could not tell if the pressure side is accurate. Recommend replacing the gauge and the pressure relief valve.