So last night I was using the spa and everything was running as normal for about two hours and then the heater did something I have never seen before. I noticed smoke coming out of the exhaust vent, since it was dark out and late, and I did not feel like messing with it I shut the heater down and left it alone.
I woke up this morning and fired the heater up again and this is what happened. First thing it did was the exhaust vent ramped up to high and stayed on for about 30 seconds. Next the fan cycled to low, and this is when I could smell natural gas around the heater, I assume that it was exiting through the exhaust vent. After another 30 seconds or so of the vent on low, I then can hear the heater light, and make the normal whistling sound when you first fire up a heater. The exhaust vent then ramped up to high again and this is when i noticed smoke coming of the vent. The smoke only lasted for 20-30 seconds and then stooped, and i could no longer smell any natural gas, and the heater worked as normal and heated the spa.
I cycled the heater on and off 3 times and the above events occurred every time. Any one have any ideas of what is going on, or how to fix it?