First i will start by saying i have a Teledyne laars mini therm boiler system with 4 zones. 1 for basement, 1 for 1st floor, 1 for 2nd floor , and 1 for H2O heater. My problems started back in October when it was time to turn the heat on. I noticed one day that the Pressure relif valve was leaking and the pressure was at 30 psi. So i called a plumber and they told me to try bleeding the lines. did that, no change. Next thing i did was replace Pressure regulator valve thinking this was the reason the pressure keft going up. Still no change. Now just the other day i just changed the expansion tank and yet still no change. The last thing i have done is bleed the pipes one last time. But the pressure still seems to be rising to 30 psi and dripping water out of the pressure relief valve. i am at my wits end and do not know what else to do besides call a plumber but dont really have the money to do that hence why i have done things on my own and now im here. Any help would be greatly appreciated!