Hello, Two things Iâ€™d look at are water pressure and the amount of softening you do. If itâ€™s a gas fired heater, there is more to consider. Starting with pressure, you want 40-60 psi with no rapid fluctuations. Iâ€™d use a 0-200 psi gauge that can ce screwed onto hose thread and put it on the heater drain. Test for static pressure and also when the heater is heating with no water being run. Let us know what you find. Next is softening. You want to leave 60-120 ppm of hardness in the water. Donâ€™t soften down to zero! When you remove the present heater, remove the anode from it and post a photo here. It may have a story to tell.