1. Communication wire disconnected.
2. Faulty Sola controller.
1. If the Touch-screen Display is not blank, but is displaying “System Disconnected!” in the middle of the screen, ensure the 4 by 1 Molex connector, located behind the display at the top, is connected and that the wires are fully inserted. If the connector appears to be fine, check the wiring connections on the back of the touch-screen display; Green, Red and Black go to terminals 1, 2 and 3 respectfully.
2. If 24VAC present at controller terminals J8 1 & 2, check Power LED on controller. Verify that connector J8 is securely plugged into the controller. Recycle power to boiler, if controller does not operate, replace the controller.