I have a 400k btu NG unit and the heater itself works fine. Trouble is the buttons to adjust the temperature are not responding. It won't allow me to change the final temperature. It doesn't matter if it's on "pool" or "spa". This has been going on for years but before I would be able to get it to change temps after fiddling with the buttons a bit but now it's finally stopped working.
Does anyone know how to test if it's the actual buttons that are faulty or if it's a control board issue? I don't want to buy incorrect parts since they're astoundingly expensive and can't be returned. I'm hoping it's just the buttons since that part is half price of the control board.
Thanks a ton for the help!