My furnace was cutting in and out in the mibble of the heating cycle.I put my ear to the side of it and the induction fan was not sounding to healthy. Fist thing I checked was the flow of condesate through the trap - flowing to drain ok. Then I checked the the condesate tubes going to the trap one on the flue and one on the transition box. Both were clear. I then took the induction fan out tipped it over to find a bunch of water/condensate in it. My guess is the water was flying around in the fan housing and interferring with the singnal to the pressure switch which is designated for the induction fan. I cleaned every thing out checked the drain on the vent fitting on the flue which collects the condensate fired the furnace and every thing is working fine. Question, how the hell did all that condensate get into the ID fan housing ? Did the drain on the flue fitting overflow and run back into the ID fan ? I hear this can be due to an incorrect slop on the flue or a sag in the flue run therefore the condesate pools and eventally rolls back down the flue overflowing the flue drain and in to the ID fan. I checked the slop required and the slop that I have and it is ok. Required- 3.5" actual- 4.5". That said when I got the ladder out and checked the exhaust flue it was and always is very wet. Alot of water droplets on the roof of the plastic piping. Now let me through this out there. I set the 'swing' (differental)on my Lux progrmmable stat to 0.5 degrees c. Excellent room temp set point control. The furnace fires on low fire for 12min and if the call for heating is still there it fires on high fire. Room temp is 95% of the time satisfied during the 12min low fire stage. Question - is this flooding out my furnace due to the fact it dosen't stay on for very long. There is alot of condesate in the flue of a gas cond. furnace, do you have to have a higher heat rise setting in order to assist in drying out some of this condensate? Just one more ?? Furnace manual says to set thermostate anticipator to 0.1 is this the same as the swing setting?? Thangs in advance, Rich