Does your shower seem more like a sand blast? Is your pressure relief valve on your water heater leaking? These are all symptoms of having too much water pressure. These are just the tip of the iceberg. Along with not having a thermal expansion tank on your system, having high water pressure is the next leading cause of failure of plumbing fixtures.
Most plumbing fixtures are made to have a working pressure from 30-60 psi of water pressure. In most cities you can expect anywhere from 100 – 200 psi of water pressure coming in from the street. This causes extreme pressure on your water heater and plumbing fixtures. Not to mention a quicker failure rate of any plumbing fixture. Most manufacturers do not warranty products that are damaged by high water pressure.