Your RV air conditioner is dripping water inside often because water made from cooling the air cannot get out the right way. This water is called condensation. It should drain outside. When it drips inside, it means something is stopping the water from going where it should go. Common reasons include a full drain pan, a blocked drain tube, the cooling part freezing up, or a bad seal around the unit on the roof. Fixing it means finding the problem and letting the water drain correctly again.
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Why Water Appears: The Simple Idea of Condensation
Air holds water. Warm air holds more water than cold air. When your RV air conditioner cools warm air, the air cannot hold as much water anymore. This extra water turns into liquid drops. This is like when a cold drink bottle gets wet on the outside in summer. Those water drops are condensation.
Your RV air conditioner has a part that gets very cold. It is called the evaporator coil. When warm, moist air from inside your RV blows over this cold coil, water drops form on the coil.
This water must go somewhere. RV air conditioners are made to collect this water. They have a system to carry it outside. When this system does not work right, the water drips inside your RV. This is the main reason for condensation problems RV air conditioner issues.
The Drain Pan Is Full
One common reason for water dripping inside is that the RV AC drain pan overflowing. The drain pan is a small tray right under the cold evaporator coil. It catches the water drops that form on the coil.
This pan has a hole or a tube connected to it. This hole or tube lets the water flow out of the pan and off your RV roof.
If the drain pan fills up with water, it can overflow. Where does the water go when it overflows? It spills over the edges of the pan. Inside your RV, this water shows up as drips from the AC unit.
Why would the drain pan fill up?
* The drain hole is blocked.
* The drain tube is blocked.
* There is too much water for the system to handle quickly.
We will look at blockages next. But sometimes, even without a full block, the water just backs up in the pan if it cannot flow away fast enough. This leads to the RV AC drain pan overflowing.
Checking the Drain Pan
It is hard to see the drain pan without taking parts of the AC unit apart. The drain pan is usually located just under the evaporator coil, inside the upper part of the AC unit on your roof.
You can often see signs of an overflowing pan by looking at the bottom part of the AC unit inside your RV. If water is coming from the middle section where the cold air comes out, it might be the pan.
To really check the pan, you might need to go on the roof. You would need to remove the outer cover of the AC unit. Be careful doing this. Make sure the power to the RV is off. Inside the unit, look for the pan under the coiled pipes. See if it has standing water in it when the AC has been running.
If the pan is full, the next step is to check the drain path.
The Drain Path Is Blocked
The most frequent cause of an RV AC drain pan overflowing is a clogged RV air conditioner drain. The drain path is how the water gets from the drain pan out of the unit and off your roof.
This path is usually a small tube or a channel built into the AC unit base. It goes from the drain pan to an edge of the unit, letting water drip off the roof.
What blocks this drain path?
* Dirt, dust, and grime from the air that the AC pulls in.
* Mold or mildew that grows in the wet environment.
* Leaves, bugs, or small debris from outside getting into the drain opening.
* A spider web inside the tube.
When the drain path is blocked, water cannot leave the drain pan. The pan fills up. Then it overflows inside your RV. This is a very common condensation problems RV air conditioner source.
Clearing a Clogged Drain
Clearing a clogged RV air conditioner drain is often the first thing to try when you have water dripping inside.
Here is how you can often do it:
1. Turn off all power. Make sure the RV’s main power and the AC power are completely off. Safety first.
2. Go on the roof. You need to get to the AC unit on top of your RV.
3. Remove the outer cover. This is usually a plastic shell held on by screws. Take it off carefully. You might need a screwdriver.
4. Find the drain opening. Look around the base of the AC unit, usually on the sides or corners. You are looking for a small hole or a tube end where water should drip out onto the roof. Sometimes there are two.
5. Check for blockages. Look into the drain opening. Can you see dirt, leaves, or other stuff?
6. Clear the blockage. You can use a few things:
* A small, flexible wire (like from a coat hanger). Gently push it into the drain hole or tube to break up clogs. Do not push hard. You do not want to poke a hole in the pan or tube.
* Compressed air. If you have a can of compressed air (like for cleaning computers), you can try blowing air into the drain opening from the outside. This might push the clog out.
* Water. Some people use a turkey baster or syringe to gently push water into the drain opening. This can sometimes push a blockage free. Be careful not to flood other parts of the unit.
* Vacuum cleaner. Sometimes you can use a wet/dry vacuum to try and suck out the clog from the drain opening on the roof.
7. Clean the drain pan. If you can see the drain pan inside the unit after removing the cover, carefully clean out any dirt, mold, or slime. Be gentle. Do not damage the pan or the coil above it.
8. Pour some water. After clearing the drain, pour a small amount of water into the drain pan (if you can access it) or near the drain opening. Watch to see if it flows out freely onto the roof.
9. Put the cover back. Once you are sure the drain is clear and water flows out, put the outer cover back on the AC unit.
10. Test the AC. Turn the power back on and run the AC. Watch inside to see if the dripping has stopped.
If the drain was the problem, clearing it should fix the dripping inside. This is a key part of fixing RV AC dripping inside.
The Evaporator Coil Is Freezing
Another major cause for water dripping inside is when the RV AC evaporator coil freezing. The evaporator coil is the part that gets very cold. If it gets too cold, ice can form on it. This is also called RV air conditioner icing up.
Ice forms on the coil for a few reasons:
* Poor airflow: Not enough warm air from inside the RV is blowing over the cold coil. This is a very common cause.
* The air filter inside your RV is dirty. A dirty filter stops air from moving freely.
* The fan inside the RV unit is not working right or is blocked.
* The vents inside your RV are closed or blocked, stopping air return to the AC unit.
* Low refrigerant: The AC system does not have enough of the special liquid (refrigerant) that makes things cold. This makes the coil too cold in some spots, causing ice.
* Running in very cold weather: Using the AC when outside temperatures are too low can cause icing. RV ACs are made for cooling hot air.
* High humidity: Sometimes, very high humidity combined with other issues can make icing worse. Excess humidity RV AC drip can happen when ice melts.
When the evaporator coil freezes, it gets covered in a layer of ice. This ice is frozen water that should have drained away as liquid.
When the AC unit turns off (or sometimes even while running), this ice starts to melt. It melts quickly. It makes a large amount of water all at once. The drain system cannot handle this sudden flood of water. The drain pan overflows, and water drips inside your RV. This can also cause the RV AC not cooling and leaking problem, as the ice blocks airflow and stops cooling, then melts and leaks.
Dealing with a Frozen Coil
If you suspect your RV AC evaporator coil freezing is the problem, here is what to do:
- Turn off the AC immediately. Do not just turn off the cooling; turn off the entire AC unit at the thermostat or breaker.
- Let the ice melt. This can take several hours, depending on how much ice there is and the outside temperature. You can turn on the fan-only mode (if your unit has it) to help move air over the coil and speed up melting.
- Catch the water. As the ice melts, be ready for water to drip inside. Place towels or buckets under the AC unit inside your RV to catch the melting ice water. This is why it was dripping inside!
- Find the cause of the freezing. Once the ice has melted and the dripping stops, you need to figure out why it froze.
- Check the air filter. This is the easiest check. Find your RV AC air filter inside the RV. It is usually in the ceiling unit. Pull it out. Is it dirty? If it is, replace it with a new one or clean it if it is reusable. A dirty filter is a very common reason for poor airflow and freezing.
- Check return vents. Make sure the air return vents inside your RV ceiling unit are not blocked by anything.
- Check supply vents. Make sure the vents blowing cold air into your RV are open and not blocked. Good airflow throughout the RV helps prevent freezing.
- Listen to the fan. Does the fan sound strong? Is it running at the correct speed? A weak fan means poor airflow.
- Consider low refrigerant. If airflow seems good and the coil keeps freezing, you might have low refrigerant. This is a job for a trained RV AC repair person. Adding refrigerant is not a simple task and requires special tools and knowledge.
After letting the coil thaw and fixing the cause (like changing the filter), you can turn the AC back on. Watch it closely to see if it cools correctly and if the dripping has stopped. If it freezes again, the problem is not fixed, or you might have a refrigerant issue needing professional help. This is a key step in fixing RV AC dripping inside when freezing is the cause.
The Seal Around the Unit Is Leaking
The RV air conditioner unit on your roof sits in a big hole in the roof. There is a seal between the bottom of the AC unit and the roof of your RV. This seal is usually a thick rubber or foam gasket. Its job is very important. It keeps outside water (like rain) from coming into your RV through the roof hole. It also helps seal the ductwork for the AC.
If this RV roof AC gasket leak, water can get past it. This water might be rain. It might be water from the AC’s drain pan backing up near a weak spot in the seal. Or it could be melted ice water finding a way around the main drain path and through a faulty seal.
When the seal leaks, water comes in around the edges of the AC unit inside your RV, not necessarily from the middle like with a drain pan overflow or melting ice. It can stain the ceiling or run down the walls near the AC unit.
A seal leak is different from condensation problems RV air conditioner issues from the drain system or freezing. It is often a structural leak.
Checking and Fixing the RV Roof AC Gasket Leak
Checking the seal requires going on the roof.
- Turn off all power. Safety first.
- Go on the roof.
- Look at the base of the AC unit. The unit is bolted down to the roof. The seal is squished between the unit and the roof. You might see the edge of the old seal.
- Check the tightness of the bolts. Inside your RV, under the AC unit’s plastic cover, there are usually bolts that hold the unit down to the roof. These bolts squeeze the seal. If they are loose, the seal might not be tight enough. Before you tighten bolts, understand that overtightening can crush the seal and make it worse. Look up the correct torque (how tight they should be) for your specific AC model. Usually, you tighten them just enough to compress the gasket properly, often measured by how much the gasket is squeezed.
- Inspect the seal itself. If you can see the gasket edge from the roof or the side, look for cracks, tears, or flat spots where it is not sealing well.
- Consider replacing the seal. If the gasket looks old, cracked, or damaged, it might need to be replaced. This involves:
- Removing the outer AC cover on the roof.
- Disconnecting any wires (make sure power is OFF).
- Unbolting the unit from the roof (you often do this from inside the RV).
- Lifting the heavy AC unit off the roof. This is usually a two-person job.
- Removing the old gasket material completely.
- Cleaning the roof area where the AC sits.
- Placing a new, correct gasket for your model AC unit.
- Carefully lowering the AC unit back into place.
- Re-bolting the unit from inside, tightening bolts evenly and to the correct tightness.
- Reconnecting wires (make sure you get them right).
- Putting the outer cover back on.
Replacing the roof gasket is a bigger job than clearing a drain or changing a filter. If you are not comfortable lifting heavy objects or working with wiring, it might be best to get professional help for an RV roof AC gasket leak.
Other Potential Seal Points
Besides the main roof gasket, there can be other places water might leak.
- Condensate pan seal: Sometimes, the drain pan itself is a separate piece that seals to the rest of the unit. If this seal fails, water can leak out before it even reaches the drain opening. This is less common but possible.
- Unit housing leaks: Cracks in the plastic outer cover on the roof are rare but could allow rain to get in. Or damage to the base pan itself could cause leaks.
Checking seals is part of thorough fixing RV AC dripping inside efforts, especially if drain cleaning and defrosting don’t solve the problem.
Excess Humidity Makes Dripping Worse
High humidity, meaning a lot of water vapor in the air, naturally causes more condensation to form on the cold AC coil. While this is normal, excess humidity RV AC drip can happen when the system is already struggling.
Your RV AC is designed to remove some moisture from the air as it cools. This is why you get condensation. But if the air is extremely humid, the AC makes a lot more water than usual.
If your drain system is slightly slow or partly blocked, this extra amount of water from high humidity can overwhelm it faster. This makes the drain pan overflow more likely.
Also, if the air circulation in your RV is poor, humid air might just cycle over the coil without getting enough air flow, contributing to potential icing issues, which then melt and drip.
What to Do About High Humidity
You cannot change the weather, but you can help your AC manage high humidity:
- Ensure good airflow: As mentioned before, clean filters and open vents are key. Good airflow helps the AC work efficiently and handle moisture better.
- Use a dehumidifier: In very humid conditions, running a separate dehumidifier in your RV can remove a lot of moisture from the air before it reaches the AC. This reduces the amount of condensation the AC has to handle.
- Check for air leaks: Make sure windows, doors, and vents are closed tightly when the AC is on. Letting humid outside air constantly enter the RV makes the AC work harder and produce more condensation.
Managing humidity helps the AC’s drain system keep up and reduces the chance of excess humidity RV AC drip problems.
RV AC Not Cooling and Leaking: A Combined Problem
Sometimes, you notice your RV AC not cooling and leaking water inside at the same time. This often points to the frozen evaporator coil issue we discussed.
Here is why this happens:
1. The evaporator coil starts to freeze over (due to poor airflow, low refrigerant, etc.).
2. As ice builds up on the coil, it blocks the spaces between the cooling fins.
3. Blocked fins mean air can no longer blow through the coil properly.
4. Since air cannot pass through the cold coil, the AC cannot cool the air effectively.
5. The AC stops cooling your RV, or the cooling is very poor.
6. Eventually, the ice starts to melt (especially if the unit cycles off).
7. The melting ice creates a lot of water very fast.
8. This large amount of water overwhelms the drain system.
9. Water drips inside your RV.
So, the RV AC not cooling and leaking together is a strong sign that the unit is icing up. Addressing the cause of the freezing (usually airflow or refrigerant) is the solution.
Summarizing Causes and Checks
Let’s quickly look at the main reasons for dripping inside your RV and the simple checks.
| Cause | Simple Check | Simple Fix |
|---|---|---|
| Clogged RV Air Conditioner Drain | Look at drain openings on roof unit base for dirt. Pan inside is full. | Clear drain opening with wire/air. Clean drain pan. |
| RV AC Drain Pan Overflowing | Water drips from the middle of the inside unit. Pan inside is visibly full. | Usually caused by a clogged drain. Clear the drain. |
| RV AC Evaporator Coil Freezing | AC cools poorly or not at all. Unit sounds like it is running. Ice on coil. | Turn off AC, let ice melt. Check and replace air filter. Check airflow. |
| RV Air Conditioner Icing Up | Same as above. Poor cooling and ice build-up on the coil. | Same as above. Address airflow issues (filter, vents) or possible low refrigerant. |
| RV AC Seal Leak / RV Roof AC Gasket Leak | Water drips from the edges of the inside unit, often near walls. Stains near unit. | Check tightness of mounting bolts (do not overtighten!). Inspect gasket condition on roof. Replace gasket if bad. |
| Condensation Problems RV Air Conditioner | General term for water issues. Can be any of the above. | Check all potential causes: drain, freezing, seal. |
| Excess Humidity RV AC Drip | Dripping is worse in very humid weather. | Ensure good airflow. Use a dehumidifier. Seal RV against outside air leaks. |
| RV AC Not Cooling and Leaking | AC running but no cold air, and water drips. | Likely freezing coil. Address airflow or refrigerant issue. |
These are the most common reasons fixing RV AC dripping inside.
Keeping Your RV AC Happy: Prevention Tips
Preventing water drips is easier than fixing them. Regular care of your RV AC unit can save you trouble.
Clean or Replace Air Filters Often
This is the single most important and easiest thing you can do. A clean filter means good airflow. Good airflow prevents freezing and helps the AC manage condensation properly. Check your filter every month during use and clean or replace it when it looks dirty.
Keep Drain Openings Clear
Make it a habit to look at the drain openings on the roof unit when you are up there cleaning or inspecting. Gently clear away any leaves, dirt, or spider webs you see near the openings. You can sometimes gently poke them with a soft brush or a toothpick.
Inspect the Roof Seal Regularly
When you are inspecting your RV roof for leaks, also look at the base of the AC unit. Check the seal around it. Does it look cracked or damaged? Does it look like it is lifting anywhere? Catching a problem early can prevent a bigger leak later.
Run the AC Smartly
- Avoid running the AC on the coldest setting constantly, especially in moderate temperatures. This can increase the chance of freezing.
- Make sure all vents are open and not blocked when the AC is running.
- If your RV has been closed up in very high humidity, consider airing it out briefly or using a fan before turning the AC on full blast.
By taking these simple steps, you reduce the chances of dealing with a dripping RV air conditioner later.
When to Call a Professional
While many RV AC drip problems can be fixed by the RV owner (cleaning drains, changing filters), some issues need expert help.
You should consider calling an RV repair technician if:
* The problem is not fixed after you have cleaned the drains and changed the filter.
* You suspect low refrigerant is causing the coil to freeze. Dealing with refrigerant requires special tools and is regulated.
* You need to replace the roof gasket and are not comfortable lifting the heavy unit or are unsure about the process.
* You hear strange noises from the unit.
* The AC unit simply does not cool at all, even without dripping.
A professional has the right tools to properly diagnose and fix more complex AC problems, including accurately checking refrigerant levels and repairing electrical issues.
Final Thoughts on Dripping Water
Finding water dripping inside your RV can be worrying. It suggests a problem that needs attention to protect your RV’s interior from water damage. Most of the time, the cause is related to how the AC handles the condensation it creates.
The water is supposed to form on the cold coil, collect in the drain pan, and flow out through a drain path onto the roof. When this path is blocked (clogged RV air conditioner drain), the pan overflows (RV AC drain pan overflowing). When airflow is bad, the coil freezes (RV AC evaporator coil freezing, RV air conditioner icing up), creating a lot of water when it melts. Sometimes, the seal around the unit on the roof leaks (RV AC seal leak, RV roof AC gasket leak), letting water in from outside or from AC issues. High humidity can make any of these condensation problems RV air conditioner worse (excess humidity RV AC drip). If the unit is not cooling and leaking, it is often freezing up (RV AC not cooling and leaking).
By understanding these simple reasons and knowing how to check and fix the common ones like cleaning drains and filters, you can often stop the dripping yourself. Regular care, like cleaning filters and checking drains, is your best defense. If the problem is complex or you are unsure, calling a professional is a good idea to ensure your RV stays dry and cool. This guide helps with fixing RV AC dripping inside.
Frequently Asked Questions (FAQ)
h4> Is the water dripping from my RV AC unit dangerous?
The water itself is usually just condensation, which is clean water from the air. However, dripping water inside your RV can cause damage over time. It can ruin ceiling panels, cause mold or mildew growth, and damage wood or other materials. The drip itself is not dangerous, but the water damage it causes can be.
h4> How much water is normal for an RV AC to produce?
An RV air conditioner can produce a surprising amount of water on a hot, humid day. It can be several gallons over a few hours. This is why the drain system is so important. If you see a lot of water dripping off your roof from the AC unit when it is running, that is normal. Dripping inside is the problem.
h4> Can I use tape to fix a leaking RV AC seal?
Using tape on a leaking roof seal is usually a temporary fix at best. Tape will likely not create a waterproof seal that lasts, especially on a surface exposed to sun, rain, and temperature changes. The correct way to fix an RV roof AC gasket leak is to replace the old gasket with a new one made for your unit.
h4> My AC filter looks clean, but the coil is still freezing. What else could it be?
If your filter is clean and vents are open, but the coil freezes, the next most likely cause is low refrigerant. This is a problem that requires a professional AC technician to diagnose and fix. It is not a DIY job because refrigerant is a sealed system and needs to be handled properly.
h4> How often should I clean my RV AC filter?
It depends on how much you use the AC and how dusty the conditions are. A good rule of thumb is to check it at least once a month when you are using the AC regularly. Clean or replace it when it shows visible dirt build-up.
h4> My AC is dripping, but only when it rains. What does this mean?
If the dripping only happens when it rains and the AC is running or even off, it strongly suggests an RV roof AC gasket leak. The rain water is getting past the seal on the roof and finding its way into your RV. Check the gasket seal carefully.
h4> Can I pour water down the AC drain from the inside?
It is better to try and clear the drain from the outside (on the roof) or by cleaning the drain pan inside the unit if you can access it. Pouring water down from the inside might just add to the water that is already backing up and make the internal dripping worse if the blockage is severe. Use small amounts if attempting to flush.
h4> Why does my AC only drip inside sometimes?
Intermittent dripping can happen if the drain is only partly blocked. Water might drain slowly most of the time. But on very hot, humid days (more condensation) or if the unit runs for a long time, the drain can’t keep up, causing it to overflow briefly. It could also be minor icing that melts only after long run times. Keep an eye on it, as a partial blockage often becomes a full one.
h4> Is it safe to go on my RV roof?
Be very careful when going on your RV roof. Make sure your ladder is stable. Walk only on areas that are strong enough to hold your weight. If you are not comfortable or able to safely get on your roof, it is better to hire someone who can. Safety is important.
h4> Can mold grow because of the dripping water?
Yes, dripping water and the moisture it creates inside your RV can lead to mold and mildew growth. Mold can grow quickly in damp, enclosed spaces like an RV. It is important to stop the dripping water problem as soon as possible to prevent mold and protect your health and RV structure.