Hot water Whistling when it flows

[Cindy and Ray's Grand Tour]

The hot water is making a hum/whistling when flowing from any of the faucets. It was doing it before the water heater was drained for the winter and it is still doing it after a month of use. Any ideas why it does this? Also my water pressure seems low with or without a pressure reducer. I asked Camping World to check the pipes during my annual maintenance and they thought it was good but I am not too sure I trust CW's opinion. It is going somewhere else for maintenance this fall.

[DQDick]

Could be that you have mineral deposits in there and, if so, some of it can flake off and begin to clog the screens on your faucets cutting down the flow. Since most of the places we go have really hard water we use a portable water softener to correct the situation.

[Daryles]

Check the aerator on each faucet for debris

[BB_TX]

May be the check valve on the WH outlet not openly all the way.

[ChuckS]

My vote would be a sticking check valve on the hot water outlet side of water heater tank