I have the same problem as other people have with the condensation shutting off the furnace.I followed the suggested solution by cleaning the tubes and draining the water from the system and it would run for a few days,I drain mine daily to avoid it shutting off. My question is, should the drain coming from the furnace to the floor drain have a P trap to create a vacuum in the system, as mention on a video I seen on HVAC systems.

Thanks Garey

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P trap to create a vacuum in the system

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P traps do not create a vacuum. P traps are a water seal.

You see them on heat pumps outside to keep insects out of the drain system.
You see them on high efficiency furnaces to prevent blowing warm air to the exterior if vented to the outside,
or the plumbing drain if connected to a drain pipe.
If you drain is not trapped and drains to a floor drain, you will simply get a little warm air out the condensate drain.