Hoping someone can help or give me a suggestion. Recently my CO2 tank tipped over iin the refrig and as bad luck would have it, it landed just right so that the CO2 stem broke off right at the locking nut. I just replaced the CO2 stem, refilled the CO2 tank and hooked the system back up. When I turn the CO2 on, it's (CO2)immediately coming out of the pressure relief valve and I cannot figure out why. It's loud and I have to immediately turn the CO2 tank off. I even have the adjusting knob on the regulator turned completely to the left (counter clockwise). Any ideas?