[Zass38]

One of the issues that could contribute to the high water pressure spikes is water hammer. This can happen when your dishwasher or washing machine stops the water, or any automatic valve.

Generally, this is taken care of by a "surge tank" or air column in the water line. This is an easy install. I believe in the newer houses surge tanks are installed, but they must be reset over time to ensure that there is an air cushion to eliminate water shocks.

Just a thought .....