Product review (5 stars): Works Great for Aprilaire 600A
Used this to replace dead solenoid on an Aprilaire 600A. As stated by other reviewers, this unit did come "Backwards" compared to my old one, but simply loosen the nut on the top of the solenoid a fraction and turn the bracket around to the other side, then re-tighten and install.. super simple and works as it should.