Distribution fan in my Harman P38 shuts down.........

.......when I set the feed rate below #2. It seems the flame is just too low and does not put out enough heat . I would think the exhaust sensor probe (ESP) is sensing the lower heat output and turning the blower off..
Can someone confirm this and is this normal?
I was under the impression the fan would operate at the #1 setting or at least at #1.5.
I`m an electrician and getting it to run at any temperature wouldn`t be difficult but maybe it will work fine as it is.
John

my p38 does the same.. the distribution fan will come on when every 10 to 15 minutes for about 4 to 5 mins and shut off again.Im assuming there just not enough heat to keep it running and itwould end up blowing cold air.

Thanks for the quick reply rayttt.
John