I have a down east spa that has stopped heating. I thought this was due to a flow problem so I replaced the filter, drained the water and figured I'd start from scatch. When starting up the spa it goes through its start up functions and when it gets to the Pr function nothing happens. then the heat light comes on for about 30 seconds goes off and the dr code comes up. I took the filter out and tried again and the same thing happened . I was wondering if anyone could help me with this problem before I call a tech .This is the windsor model. Any help would be greatly appreciated .