I had a new water heater installed recently. Since the installation, the pressure relief valve has been leaking. The installer tested the house water pressure and said it was too high. I just had a new house water pressure regulator installed @ an even lower water pressure than before. The old water heater has never leaked prior to the new one being installed. I don't know what the pressure was before but I now have it set @ 56 PSI. And that is less that what I had before. Is it possible the pressure relief valve on the heater is faulty? How can I check the water heater pressure ?