Banging pipes when water is turned on
Recently I noticed the house water pressure was higher then usual. I checked and it was 85 psi instead of the usual 50-60. I called a plumber to replace the 20 year old pressure regulator, the pressure now looked good but and then the banging started. This never happened in the previous 20 years. Sometimes when running the washer, and it starts to fill the pipes will start a rapid banging. The plumber came back out and replaced the shut off valves at the washer and added water hammer arresters as well. This did not solve the problem and it does it as well when turning on the water in a bathroom tub. Various web sites speculate this could be air bubbles in the system so we tried opening all the faucets in hopes the air bubbles would flow out of the system. It was looking good in that we did three loads of laundry without a problem. Unfortunately it still happens in the tub, and most likely the washer next time it is used. The tub has a single handle faucet that you pull out to start the flow. Pulling it out fast seems to be what causes the problem.
Why would changing the pressure regulator cause new problems with two locations. These appear to be the locations that turn on the fastest so that could be a clue. Even though it is a new pressure regulator could this banging be a caused by fluctuations is the pressure regulator? Could it be bad right out of the box?
Many thanks