Product review (5 stars): Easy to replace
It is important to keep your home properly humidified in the winter cold climates.  This part needs to be replaced whenever enough mineral deposits from your water to make evaporation difficult.  We had gone eight years before a technician doing other work suggested it was time to replace the evaporator panel.  Yep.  The instructions were good and we're probably set for another four years or so before it needs replacement again.