I have a Nordic hot tub and just replaced the presure switch because I had FLC displayed. When I turned the system back on it displayed HL. The water is cool. Turned unit off and let it sit for awhile, restarted and it still displays HL.

Don't know if this has anything to do with the problems I'm having now but 3 months ago the plastic that was wrapped around the foam in the cover disintegrated and small particles fell in the water. Got most of it out but there were still small plastic partictles floating in the water. Could these particles have pluged something up or does this sound like a mechanical or electrical problem.