It is likely that your AC roof gasket is responsible for water entering your RV only when it rains. Roof gaskets are foam gaskets that stick to the roof and sit between the AC and the roof. In order to prevent rainwater from entering your RV, bolts are used to compress the gasket between the roof-mounted part of the AC and the ceiling assembly. Locate the four bolts under the ceiling assembly and remove the plastic cover to resolve the leak. The bolts should be tightened using the appropriate socket size. Adding extra compression to the bolts will often stop the leak by resealing the gasket. It may be necessary to replace the gasket if the bolts are already snug.
Drain pan overflowing
A drain pan is used to hold the components of the roof portion of your RV air conditioning system. It is the drain pan’s responsibility to catch condensation that drips from the evaporator coil during the cooling process. During the drainage system of your RV, water collects in the drain pan and is then discharged through a drain hole onto the roof. When the AC is operating, you will notice water running off the roof of your RV. In the event that a drain hole becomes blocked, debris accumulates in the drain pan, preventing water from reaching the drain pan; as a result, water will eventually find its way into the RV as it needs a place to go. Water leaking into the RV is also possible as a result of cracked and failing caulking or a crack in the drain pan itself. However, this is a fairly rare occurrence. In addition to removing the shroud from the roof portion of the AC, you will also need to clean the evaporator coils, as dirty coils can also cause issues.
When warm air cools, it undergoes a condensation process. A particularly hot and humid climate will usually result in condensation forming on almost any cool surface in the AC or ducting system. There is little that can be accomplished in these conditions. It is recommended that RVers run their AC fan at a slower speed in order to reduce the chance of icing on the evaporator and condensation in the ductwork.