Performed routine flush on two 50 gallon electric water heaters While performing flush, noticed that water pressure in plumbing system was very high. Pressure was above 100 psi. Recommended range is between 50 to 70 psi. This was due to poor quality pressure regulator installed by builder. These poor quality regulators tend to last between 2 to 5 years on average. This one was 4 years old. Highly recommend replacing it with a new high quality whole hoke pressure regulator to address extremely high pressure. Noticed that there also was no thermal expansion device present either to address pressure increases in plumbing system due to thermal expansion when water heaters heat water up. Recommend installing a thermal explain tank to address this issue Also, found no check valve present on cold inlet to water heaters to prevent cross connection of hot and cold water lines due to the recirculation line. It is required to have a check valve installed in cold inlet to water heaters as well