Howdy,
I have a year old Whirlpool fridge. Water filter change light did its
green-yellow-red routine right at six months, and again at one year.
I am strongly suspecting now that this is a timer, and their is no H2O
quality being measured. It would be surprising if their was a
conductivity meter in an $1100 fridge. And the filter was around $50
at Lowes.
Just wondering (yes, I live alone! Too much time on my hands!)
Carl