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Why Do My RV Tanks Gurgle?

It’s a sound no RVer ever likes to hear – the dreaded RV tank gurgle. It’s a surefire sign of trouble for your crucial black tank.

Unfortunately, not everyone knows what to do to avoid it, risking serious (not to mention expensive) damage. So why exactly do your tanks start gurgling, and what can you do to prevent it?

We break it down for you.

What Is an RV Tank Gurgle?

Simply, an RV tank gurgle is the sound that emerges from your toilet post-flush in certain situations. It’s also known as burping, as it also resembles the sound of a person emitting gas.

And as you might expect, it’s a sign that not everything is going well in your tank when it comes to disposing of your waste.

Why Is My Black Tank Gurgling?

The sound you hear when you experience an RV tank gurgle is the sound of air escaping your black tank. As you add waste by flushing, it displaces the air that previously occupied that space.

Under normal circumstances, that air is simply released out of your rig using your black tank vent. But there are two situations where this may not happen correctly.

First, your tanks may be too full to release air via the vent properly. Alternatively, you may have a clog in your black tank vent.

Woman checking RV tank system
If you hear a gurgle, it is time to start investigating your RV tank system.

How Do I Know If My Black Tank Vent Is Clogged?

The RV tank gurgle is the surest telltale sign that your black tank vent is clogged or having other issues. Your first step should be to empty your black tank as completely as possible.

If you’ve already done this and are still hearing a gurgle, a clog in your vent is likely the culprit. You may also experience unpleasant sewage odors due to the clogged vent. After all, the waste in your tank will emit some foul smells. Without anywhere else to go, they’ll creep back up into your bathroom. 

Pro Tip: Your RV tanks system is complicated. Learn more about How to Dump an RV Black Water Tank.

How Do You Unclog a Black Tank Vent? 

First, you’ll need to start with an empty tank. If you’re lucky, this may resolve your RV tank gurgle issues, and you won’t need to go any further. If the normal process of emptying your tank doesn’t do the trick, your next best bet is to use specialized RV tank cleaning products. You can purchase these at most RV or camping stores and online. 

Follow the directions, which usually consist of adding a chemical cleaner to your toilet and then adding water. These cleaners should dissolve any stubborn waste or other products blocking your vent and causing problems.

If your clog issues persist, locate the external portion of your black tank venting system. This is generally located on the roof above the bathroom area.

However, it may be in different places on some RV models. You may need to use pressurized water, air, or a toilet snake (or similar device) to remove any physical obstructions in the vent itself. 

Man holding plunger
Your RV pipe system can be complicated, so before you bust out the plunger determine where the clog is.

Can You Use a Plunger on an RV Toilet?

Technically, there’s no reason why you can’t use a plunger on your RV toilet, as long as you add some water first. But this will only help resolve clogs or other issues in the top parts of your toilet system or toilet bowl.

If your clog or issue is further down the waste lines or inside your black tank, a plunger, unfortunately, won’t have any effect at all. Therefore, you may have to try other options unless you’re sure the plunger will resolve the problem.

Can You Put Bleach in an RV Black Water Tank?

You might think bleach would be a great way to add an extra level of disinfection and sanitization to your black tank. But it’s a potentially costly mistake you must avoid at all costs.

The main risk comes from damage to your waste lines or the crucial seals they use to operate properly. Instead, those looking to kill odors and sanitize their tanks should use specialized products designed for this purpose, which protect your precious RV and its wastewater system. 

Pro Tip: Still don’t believe us about bleach in your black tank? Let us convince you further! Check out our thoughts on Is It Safe to Put Bleach in Your RV Black Tank?

How Often Do You Flush Your Black Tank? 

Whether or not you’re having issues, you should remember to flush and clean your tanks at least twice a year to prevent any stubborn buildup. If you’re a full-timer or frequently have large groups using your rig’s bathroom, you may want to throw in an additional cleaning now and then on top of that. 

While cleaning the gunk out of your black tank isn’t anyone’s idea of a good time, it’s a necessary and relatively simple chore that can save you big headaches or potential repairs down the road. And best of all, you’ll never have to worry about the dreaded RV tank gurgle showing up at an unwelcome time!

Have you ever had a problem with black tank gurgling? Tell us your story in the comments!

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