Lots of compatibility issues. The bathroom dimmer is a new Lutron. Should work with anything. But still had issues because it is controlling 2 fixtures (5 LED's,2 of one kind and 3 of another). Many of the old dimmers and lights fed from circuit boards vs direct feed, just won't work correctly. LED's are not a simple resistance from a bulb in the traditional sense. They are another circuit. Sometimes they don't play nice together.