||01-17-2011 05:33 PM
Oil Boiler Pressure Problem
I have a OIL fired Boiler system. Its 145,000 BTU Clack HMT-14. My problem is when I have the boiler cold and at 15 psi with the expansion tank at 12psi, while the burner is on warming up the boiler, the pressure seems to shoot up to almost 30psi where I either have to manually shut off the boiler or the PRV shoots on. I have tried to run the system while shutting off the manual supply line and still the same problem. I release the pressure with the manual shut off valve off and start it up again and still the same problem. Any ideas as to why the pressure is building up so much? Could the aquastat and temp gauge on the boiler be wrong/faulty? Maybe the a-stat is telling the boiler to run pass the HI ? Temp gauge on the boiler reads only 85F when the psi is at 26.