leaking Dometic AC - condensation

Drop the ceiling plate for the AC in your trailer and check the hold down bolts for the AC unit and then get on your roof, remove the AC cover and check the weeping holes on the AC base plate to make sure they are not blocked and backing up the condensate water into your unit.

Happy Prospector wrote:
Drop the ceiling plate for the AC in your trailer and check the hold down bolts for the AC unit and then get on your roof, remove the AC cover and check the weeping holes on the AC base plate to make sure they are not blocked and backing up the condensate water into your unit.

Thanks....

Check the drain holes in the condensate pan under the coils. You may have to remove the cover on your roof. Also if you do tighten the mounting bolts be careful not to tighten to much.

clean the filter and in 100% humidity you need to run the fan all the time

newman fulltimer wrote:
clean the filter and in 100% humidity you need to run the fan all the time

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happy the filter being dirty reduces airflow causes freeze up.running the fan in the on position the compressor cuts off the fan dries the coils

newman fulltimer wrote:
happy the filter being dirty reduces airflow causes freeze up.running the fan in the on position the compressor cuts off the fan dries the coils

Only issue I have with that is...........Filters are clean, AC is set to lowest output, you can hear the compressor kick on and off during the night as the fan continues to run. We stay in our 5'er 5 nights a week, AC is always on during the night and off during the day. Last night was the first time it dripped. the amount of water that appeard on the bed cover, soaked an area the size of a diner plate. The only thing I can think of is, something happened between last night and the night before. I'll do an inspection today after work.

Under the evap coil is a drip pan with drain holes that allow condensation from evap coil to drain out onto roof and run off.
High humidity causes high condensation to collect......if drip pan drain holes are plugged/blocked the condensation will overflow drip pan and leak inside the RV. Can also get carried over by fan into discharge plenum.

To access evap coil drip pan/drain holes you have to remove roof shroud and then remove sealed cover over evap coil. I even have to slip evap coil out of position to access the drain holes on my drip pan.

The A/C Unit roof opening is sealed with a gasket. 4 hold down bolts are used to secure unit to roof and compress the roof gasket.
Rain and condensate from drip pan overflowing can leak under roof gasket if the hold down bolts are loose.
To access the hold down bolts you have to remove ceiling grill.
Bolts are in the 4 corners.
They should be 'snug'........do not overtighten them. The roof gasket can be distorted if over compressed and can also block the drip pan drain holes.
'Snug'.......well that means finger tighten bolts then just a slight turn with a wrench (it is something like 20 INCH pounds of torque. Notice that is INCH LBS not foot pounds)

Old-Biscuit wrote:
Under the evap coil is a drip pan with drain holes that allow condensation from evap coil to drain out onto roof and run off.
High humidity causes high condensation to collect......if drip pan drain holes are plugged/blocked the condensation will overflow drip pan and leak inside the RV. Can also get carried over by fan into discharge plenum.

To access evap coil drip pan/drain holes you have to remove roof shroud and then remove sealed cover over evap coil. I even have to slip evap coil out of position to access the drain holes on my drip pan.

The A/C Unit roof opening is sealed with a gasket. 4 hold down bolts are used to secure unit to roof and compress the roof gasket.
Rain and condensate from drip pan overflowing can leak under roof gasket if the hold down bolts are loose.
To access the hold down bolts you have to remove ceiling grill.
Bolts are in the 4 corners.
They should be 'snug'........do not overtighten them. The roof gasket can be distorted if over compressed and can also block the drip pan drain holes.
'Snug'.......well that means finger tighten bolts then just a slight turn with a wrench (it is something like 20 INCH pounds of torque. Notice that is INCH LBS not foot pounds)

Very nice explanation. Let me add that you might first look at your roof and perhaps you will see "trails" where the water has previously run off but are now dry. That type of clue and Old Biscuits diagram should help you along.

I get plenty of bugs and wasp nests under my A/C and need to clean it up annually.

Run the fan on High. Every time I turn my fan on low so we can hear the TV it either freezes up or I get condensation on the ceiling vents. It doesnt get a chance for the fan to dry out the evaporator.