I have an old MiniMax CH 200 pool heater. It worked intermittently last year but this year I'm not getting any heat. The pilot lights and stays lit fine. Looking around on the Internet I've seen several people talk about thermocouples going bad. I cleaned some carbon off it with sandpaper but it didn't make a difference. I've measured the voltage at the terminals where the thermocouple connects to the gas valve and I was getting about 60 mV, I have no idea what it should be though.
Any suggestions of things to look at? Should I consider replacing the thermocouple?