When I turn on the cold water or flsh the toilet, there is a horrible rattle noise coming from the directioin of the water softner, however the hot water heater is in that corner of the garage as well. The noise is so bad is seems like the house is rattling apart

Softener has Push-Valve. Push it one way then the other way. See if the noise continues.

Softener has ON/OFF Push-Valve. Push it one way then the other way. See if the noise continues.