Does Your RV Air Conditioner Leak When It Rains? Do THIS!

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Rain on a camping trip is never ideal. And it becomes worse when you notice the AC unit leaking water into your RV.

So, if your RV air conditioner leaks only when it rains, we’ve compiled a list of the most common causes and how to fix them, as well as tips for preventing AC leaks in the future.

Important: Before we begin, let’s be sure your unit is leaking rainwater and not condensation (two very different scenarios). The best way to tell is when you notice the water leaking from your RV’s AC unit. If it’s a regular occurrence, regardless of the weather, you may have a condensation runoff and caulking problem. If you only see leaking when it’s raining, the problem is likely the result of one of the below issues.

Common Culprits Causing RV Air Conditioner Leaks When It Rains

Even though an RV air conditioner leak is a big deal, the fixes are typically affordable and easy to do yourself.

However, if you ever have doubts about completing the RV air conditioner repair correctly, I recommend calling a certified technician.

AC Mounting Bolts And Rubber Gasket

When mounting an air conditioning unit onto the roof of an RV, a rubber gasket and mounting bolts are required to lock it into place. One or both of these parts can shift or become damaged, causing leaks over time.

The rubber gasket is clamped between the top of your RV and the air conditioning unit. It prevents water from sneaking in through seals or connection points. But rubber breaks down with continuous exposure to the elements.

Check your rubber gasket to see if it’s hard or brittle. The less flexible it is, the more likely it is to fail at its job and allow water to enter your camper. Replace it when it becomes worn.

The mounting bolts hold the rubber gasket in place. The vibration of bumpy roads can loosen these and cause leaks. Be sure they’re tightly attached to the roof.

As a bonus, ensuring the bolts are tight and the seals fresh will not only help prevent any leaks when it rains, but it may also help your RV air conditioner run quieter!

RV Roof Damage

The shape and orientation of an RV’s roof will sometimes make it hard to discern the origin of the water dripping down from your ceiling. Water often enters the roof somewhere and runs down to the lowest point, which allows it to escape.

Check your entire roof for cracks and damaged caulking. Marker lights, plumbing vents, antenna connections, ladder mounts, and other roof components can cause your air conditioning unit to leak water when it rains.

Tip: If the rubber roofing on your camper is starting to wear and crack, it may be time to replace it! Check out our guide on how to install a new rubber roof on a camper.

RV roofs can also begin to deteriorate due to exposure to the elements. A deteriorating roof becomes weak, and the air conditioner’s weight may cause it to sag more in the area around it.

Check to see if your roof is level. You can use an actual level or pull a string tightly across the top of the camper. If this is the cause of your leaking roof, you’ll typically see a substantial amount of sag.

Raise and reinforce the area around your air conditioner opening to prevent further leaks and damage. Shims, gaskets, or specialty trim rings will help strengthen the area and prevent water from pooling around the opening.

Tips to Prevent Leaks From Returning

The best way to prevent your RV air conditioner from leaking when it rains is to check your roof and AC unit regularly.

These checks should be a part of your camper winterization and de-winterization plans and whenever you wash your vehicle or clean your air conditioner filter. With these routine inspections, you’ll notice cracks in the caulk, water pooling on the roof, or worn gaskets before they cause problems.

It’s essential to take care of these situations before they lead to more significant problems. Even though it can be a hassle, I recommend climbing up onto your RV roof and inspecting it at least every month or two.

Professional RV AC Inspection

Most RV repair shops offer roof inspection services. During these assessments, a technician will also check your air conditioning unit to ensure it works as designed.

Tip: I recommend a yearly professional inspection of your RV roof in addition to your regular checkups. Consider scheduling your appointment in the spring before the hot temperatures of summer hit or in the fall before you winterize your rig.

It’s helpful to have a professional’s eyes on your motorhome roof to find developing issues you might miss.

3 thoughts on “Does Your RV Air Conditioner Leak When It Rains? Do THIS!”

  1. My leaking problem is only when it rains! And when that happens the water is somehow following the vent to the front bedroom and drips from that vent. It is the only leak, it only happens when raining. What would be your thoughts?

    • It’s most likely the gasket sealing the AC unit to the roof is bad, or the lag bolts holding it down are loose, and water is leaking into the duct. That’s where I would start looking.

      • 👍 ok I’ll check that, I was also thinking the air box might be allowing water in? It has no sealant tape, and water dose sit on the top!


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