Why is the water pressure suddenly high in my toilet after hot water heater replacement?
Try running the water for several minutes, both hot and cold sides, at the other fixtures too. Do they behave similarly? Do the symptoms diminish after a minute or two?
When a water system is opened, especially for something like a heater replacement, air gets into the pipes. Eventually the air finds its way out through the various faucets. As bubbles of air exit the faucet they make a lot of noise. They also can cause the water to eject forcefully. It sounds and looks a lot like the water pressure had been increased even though that's not actually the case. Running the faucets for a few minutes allows the air to be purged from the system and it'll behave normally again afterward.