It is forced air but different from the your link.
The 2 fans run coaxial from one motor.
It seems to run very well now, but it is so strange that it was mounted with the thermocouple below the pilot flame. I don't think it has ever run since installation, as I don't see how the thermocouple could ever be heated enough to latch the pilot valve, and the main gas valve would not go on without the pilot valve latched.
I would love to see a picture of the pilot manifold from an other unit.
I spent a number of hours yesterday contemplating if Duo-Therm had done something very clever that I was missing, or if it was simply installed with a special upside down version manifold. All the printing was right side up.
I suspect mine is odd because it is under the curb side settee.
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