Cleaned and checked gas boiler. Checked voltage & amp draw of pump. Inspected heat exchanger & flue venting. cleaned burners & pilot assembly. Check compression tank pressure: 12. Tested water feed regulator. OK. Regulator setting: eight psi. Pressure gauge reads six PSI higher than actual. Checked vent. Oil pump motor. Set primary air. Supply: 137. Return: 105. Pressure: 22-6= 18.