We all know the nuisance that bugs and rodents can pose to campers. But for this article, we’re not concerned with window & door insect screens that keep flying insects from entering your rig. The RV bug screens we’re referring to here are just as essential, if not more so… but they’re different. We’re talking about RV vent bug screens that cover the vents of your RV appliances. They’re easy to install, generally not expensive, and could save you a lot of your hard-earned money, or even your life.
What Are RV Vent Screens and Why Are They Important?
Most of your RV appliances are vented to the outdoors. This includes your RV furnace, water heater, and refrigerator. If you look along the sides of your RV, you’ll see the vents we’re referring to right behind the appliances. Some have long louvered openings, while others have smaller openings. All of them serve as an invitation to trouble.
The exhaust ports for an RV’s furnace are an easy entry point for all sorts of pests.
Certain bugs and other pests (particularly mud daubers) can impact the performance of your RV appliances and cause damage by building nests that interfere with airflow. Not only can these nests prevent your rig’s appliances from functioning properly, but they can also lead to hazardous situations, such as fire.
We highly recommend heavy-duty stainless steel bug screens (sometimes called “RV mud dauber screens”) for RV vents to protect your RV appliances from invasion by unwanted pests.
Can Mice Get In Through My RV Vents?
Depending on the vent, you bet they can. When we discuss protecting your rig with RV bug screens, we’re primarily concerned with bugs that tend to build nests, which can cause appliances to malfunction and require expensive repair work. Those pests are typically ants, wasps, and mud daubers.
But mice are notorious for entering RVs through the tiniest openings, and some vents on your RV may present the invitation (for much more on how to keep mice out of your rig, see our posts on how to keep invasive mice out of your RV for good, and the best mouse repellants for RV use). However, other pests can enter through specific RV vents that you might not even consider. Fridge and furnace vents are perfect examples. Check out this video to see how a colony of bats was trying to stow away on our rig!
Which RV Vents Are Prone to Nests & Pests?
Now that we’ve thoroughly freaked some readers out with our all-too-true tales of bugs, mice, and bats, let’s take a look at the most important RV bug screens that’ll keep bugs from building nests in the appliance vents of your rig, and help keep mice & bats out as well. Before we post the most common areas for pests to nest or enter, as well as the most common screens for covering these areas, we have an important note:
DO NOT use standard vinyl window screening material to cover any of these locations. These appliance vents tend to get very hot due to exhaust gases from combustion. Standard window screening material is not designed to withstand this heat and will surely melt. The only thing you should use for covering appliance vents is stainless steel external screens.
RV Furnace Bug Screen
Your RV furnace vents likely have small circular covers seen on the outside of your RV. These are not only popular nesting places for mud daubers, but, as you saw in our video above, they can also serve as an entrance into the RV for bats and other pests.
We popped these exact screens onto the outside of our former motorhome, and we never had a problem thereafter. For less than $20 and a couple of minutes of your time, you can prevent unwanted pests from entering your rig and causing problems with your furnace. As always, you’ll need to adjust the type of screens you buy based on what your furnace vents look like, but RVs with DuoTherm and Suburban furnaces (as well as others) commonly use these 2.75″ x 1.25″ circular mud dauber screens:
- RV furnace and fan unit outside fittings
- Fits DuoTherm and Suburban
If your furnace vents are different, you may require one of the other shapes/sizes of bug screens below:
- RV furnace and fan unit outside fittings
- Fits Coleman, Hydroflame, Sol-Aire and Suburban
- RV furnace and fan unit outside fittings
- Fits M500 series
RV Hot Water Heater Bug Screen
Your RV’s water heater vent is another popular nesting place for wasps and mud daubers. To keep them out, install a water heater bug screen, such as the ones linked below. Once again, measure the outside of your water heater vent (located on the outside of your RV) to determine which type of screen will fit best. The following two products are compatible with many Atwood and Suburban vents, and both are made of stainless steel.
The first measures 8.5″ x 6″:
- Quantity: the packaging includes 1 RV furnace ventilation cover or water heater ventilation cover, 4 spring hooks, and 1 installation tool, without...
- Size: each screen size is 8.5 x 6 inch (L x W), 1.3 inch in height, each mesh grid is 0.3 inch in length
This one measures 4.5″ x 4.5″:
- Quantity: the packaging includes 1 RV furnace ventilation cover or water heater ventilation cover, 4 spring hooks, and 1 installation tool; Warm...
- Size: each screen size is 4.5 x 4.5 inch (L x W),1.3 inch in height, each mesh grid is 0.3 inch in length, please check the size before purchase it
If you have a Truma water heater, or if you have an Airstream with an Alde water heater, this may be the water heater screen for you (but check your measurements):
- Keep pesky mud daubers, mice, wasps, frogs, birds and spiders from nesting in your appliances
- Stainless steel screen and springs
RV Refrigerator Bug Screen
RV refrigerator vents can vary in size as well. These tend to be long, louvered vents that require a different shape and size of screening; however, we’ll link to several options below. Note that in addition to a sidewall refrigeration vent, you may also have a rooftop fridge vent. The rooftop vent should have its own built-in mesh screen, but it’s worth taking the cover off to check it if you’re not sure.
These three screens measure 20″ x 1.5″ each. This group of screens fits Dometic refrigerator vents that have 20” long louver openings:
- Custom Fit for Dometic RV Refrigerator Vents – Designed specifically for 20” long louver openings, ensuring a secure and proper fit.
- Protects Against Wasps, Mud Daubers & Rodents – Prevents nests and blockages that can damage your RV refrigerator’s airflow.
The following screens fit Norcold fridge vents with 6.2″ X 17.8″ openings. But if you click on this link, you’ll find a drop-down menu that links you to many other shapes and sizes of Camco screens that fit many Norcold, Dometic, and other fridge vents as well:
- Designed for exterior RV refrigerator vents with 6-3/16" x 17-13/16" rough opening
- Compatible with Norcold models
Multi-Screen Kit
You can also buy a kit that contains multiple shapes & sizes of stainless steel screens for your RV’s furnace, water heater, and refrigerator vents. If the screens in the kit work for your RV, this will likely be the best bang for your buck. It includes a small tool for installing screens on all vents. Again, be sure to measure all of your RV vents before ordering a kit like this:
- PACKAGE INCLUDES: Three 10" x 1-1/2" RV Refrigerator Vent screen；Two 2.8''x1.3'' flying insect screens, One 8.5" x 6" x 1.3" RV Furnace Bug screen
- HIGH-QUALITY MATERIALS: Heavy-duty stainless steel mesh cover, absolutely strong material and corrosion-free, combination product, multi-purpose, more...
How to Install RV Bug Screens
All of the screens we’ve discussed above install in the same way. They use a small spring or two to connect the screens to a portion of the vent itself. The spring is attached using a small tool that should be included with the screens.
The screens are easy to install, but you do need to understand how the little spring connector works to prevent frustration. The best way to explain this is to offer you a visual description of the screen installation process.
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Terry Hurt
Saturday 27th of July 2024
I covered all of our vents with screens after we purchased our new camper. Our absorption fridge quit cooling. I had an rv tech come to service it. When he saw the vent screens he said many ins companies would void the warranty because it reduces air flow. He then said the only place that really needs a screen is the furnace to keep daubers out. I still have a screen over the hot water vent and furnace but have removed them from the vents behind our new absorption fridge. You might want to check with your ins company concerning vents for your fridge.
Mike Brant
Saturday 26th of July 2025
@Terry Hurt, A court case about two years ago or so threw out manufacturers'claims of warranty void because they had no data to prove that the screens, if in reasonable condition, posed any concern. There was a lot of evidence that the insects, however, posed a much higher danger to end users.
This is one of those cases where manufacturers simply didn't have a leg to stand on.
I'm beginnning to think that every RVer needs a lawyer on retainer....
Tim H.
Saturday 29th of July 2023
Thanks for the article! I’m a big fan of insect screens and installed mine shortly after we purchased our RV from the first owners.
Unfortunately- even though the original owners took very good care of the RV while they had it- one thing they had NOT done was to install insect screens and not too long after we bought it we had a furnace burner problem that was most definitely due to flying insects- I even have the photos to prove it! Lol.
In our case it wasn’t any kind of wasp or mud dauber though- it was actually “stink bugs” (not sure of their scientific name, but that’s what everybody calls them in Ohio). In the case of the stink bugs, the problem wasn’t even a nest per se, but just a densely packed collection of the dead bugs themselves.
In fact, I’ve since heard and read that stink bugs are actually attracted to the mercaptan (the chemical added to LP gas to make it smell) in and around gas appliances! Or it could just be the warm, dark and sheltered hiding place they’re after, but either way it’s just one more example of a potential bug problem that can likely be avoided by the use of insect screens. Happy trails!
Jen
Saturday 29th of July 2023
After my first storage season I ended up having to put a screen over the hole in my rubber bumper caps (where I store my black/gray tank hose). I went to dump my tanks and found a bird nest with eggs had traveled 100+ miles with me when I went to pull out my hose. :(
sparky1
Saturday 29th of July 2023
@Jen, i'll do mine today thanks,didn't think about that.