When our water softener cycles at night, our pipes “howl” and bang very loudly. It is loud enough at times to wake us up. Is this normal or what can we do to get fix it.
Find and anchor the pipe that is banging. Install a water hammer arrestor. I would imagine you have high pressure the drain noise and the diverting of pressures on your softener tank is causing the noise. Try changing the cycle time so that it happens during the day when you are not home instead in the middle of the night.