HVAC Questions? Ask an HVAC Expert for Answers ASAP
Hi, if the ductwork is too restrictive or the filter is too restrictive you will get this problem, when the door is open there is plenty of air to draw from so it does not create that vacuum that pulls the water in, you may end up cutting a hole in the return to alleviate the problem.
Where is the return? Do you mean door?
Well not the door, you want to cut the hole before the filter, air goes in one way and out the other, you want to get a hole in the duct before it enters the furnace, cut like an 8 by 8 and then you can find a grille to put over it, that will alleviate the water carry over.