I am working on a hot tub because it is not heating. I do not really know the history on it except that “it isn’t heating but it used to”. Upon inspection of the inside of the controller I located a missing fuse and a blown fuse. The flow through heater had a severely broken split nut so I replaced the gasket and split nut. I replaced the blown time delay fuse but didn’t feel comfortable and am concerned about why a fuse would be “missing”. I isolated the heater element and it metered around 11 Ohms. I tried to attach a picture of the schematic and the fuses and fuse positions but I do not have an online storage site or photobucket, etc.. Once the tub was filled, the jets work but the heater LED does not turn on and after waiting 1 hour, the temperature did not climb any. I thought that maybe the PCB was intended for multiple models and that this tub just wasn’t using the features on the side of the PCB with the “missing” PCB but I am still wondering what it controls and why there is no fuse in that location at all. The display on the top button control panel is showing "Sn" which I believe this is a sensor code error but any insight into what I am dealing with would be greatly appreciated. Otherwise, it is back in to the controller to see what else my meter can help me locate.
