A/C Sometimes Leaks Condensation Inside

[iowarver]

Just bought 1999 Mountain Aire. First time out - A/C froze up twice. Second time - Left fan on - did not freeze up but, water started leaking in from the front air intake vent. Took the filter out and it quit. Then a big stain formed on the ceiling to the left of the vent.

Where is condensation coming from and how to stop it. Had the unit cleaned and freon checked - so that is not the problem. Water seems to be running off the roof OK.

[94-Newmar]

Pull the covers on the AC units. Check to make sure no cobwebs or mouse nests or similar are blocking the trough that leads the condensation away from the coil. If they back-up bad enough they could overflow and leak inside while some of the overflow will still leave the roof ok. Check the seals on the vent thru the roof from the top side to make sure they are intact as well.

[Ernie Ekberg]

The more volume of air you have moving over the coils will stop the unit from freezing- unless before mentioned, dirty filter, nests, etc. Gotta be clean and run that baby on high during the day-- if you are here in Texas

[bigskymt]

I would try running the A/C with all the vent filters removed to increase the air flow and decrease the freezing possibility, as previously mentioned. If that has no effect then lower the thermostat to decrease the duty time, temporarily at least.........If you have a condensation problem, as you indicated, you obviously have the freezing problem solved.
If the water from the condensor leaks into the return air I'd suspect a plugged drain, also indicated and/or seals around unit base.
What's your relative humidity?

[TXiceman]

The biggest cause of the A/C freeze up is low air flow due to"
low fan speed
dirty filter
dirty evaporator coil
internal air bypass from outlet to inlet.

Start by forgetting the thing has a low speed.
Keep the filters clean.

Ken

[a k]

Low refrigerant level will freeze the coil also.

[wa8yxm]

Where is condensation coming from: Evaporator (cold) coils on air conditioner
How to stop it: Turn off air conditioner.

I know it sounds sarcastic, but .. This is the literal answer to your question.

Now on to the question you intentded to ask, which is "How do I fix it" or "What to do about it" those are somewhat more practical answers.

Water leaks into the motor home for one of several reasons, each reason has it's own cure.

1: if the evaporator coils have gotten dirty it is possible that the dirt, if "Stringy" can carry the condensation beyond the range of the drip pan and let it drip down inside. I seriously doubt this is your problem but possible it is.

2: If the drip pan has a crack, or hole in it (Plastic cracks, Metal corrordes) it can drip water where it should not drip water.. This is more likely

3: If the FRONT of the motor home is a bit lower than it should be.. Normally water drips off a drip trough on the BACK of the drip pan (Or Outlet tube) but if the rig is an inch or two "nose down" it can drip off the front edge instead.. This is fairly common.

4 If the water outlet is clogged with algae or debris (remove top cover and inspect, clean evaporator coils while at it)

5: if the mounting bolts have worked loose and allowed the unit to come off the air conditioner to roof seal a bit (Also fairly common)

6 if the roof has rotted and sagged (Possible in your case from your description) due to one or more of the above.

And last.. Since you mentioned your unit Froze UP.. .. If the ice build up is enough to ... Well, this is reason 1B when you get down to it so see reason 1

[iowarver]

Thanks to ALL! Have done as suggested. Will see how it operates next weekend. In addition, at a friends suggestion, took the covers off the four air intakes in the ceiling and ran a dry hose through the whole thing to clear any obstructions.

To be honest - was hoping to find a glaring problem but all looked good. Will see how it performs. I did leave off all the filters inside.

[RVhauler]

Had to have my Dometic A/C replaced last July at nashville camping world. Has bee run less than ten days since. It was being used by a friend for guest housing for 5 days at which time discovered condensation leakage on the ceiling. Took it into CW and during testing they found it was freezing into an ice ball. Telcon with mfg stated compressor had an electrical problem. (Personally think has refrig leak) but they are doing warranty replacement so will see if solves problem. My thoughts were a leaking roof to pan seal.