How to replace your RV roof vent fan. Here is a detailed list of instruction with pictures.
Have you ever been been stuck inside where it’s hotter than the outside? It can be pretty horrible, but there is a solution. A vent fan!
Most RV’s come with some sort of vent or exhaust fan in the ceiling. Our 2001 Lakota 5th wheel came with a 14′ x 14′ Fan-Tastic Vent roof fan. Turn that thing on high with a couple windows open on the cool side of the RV and instantly feel the cool air blowing through.
We also keep the vent fan running through the night on a low setting, just to keep fresh cool air circulating throughout the night. They really do make a tremendous difference. But, what happens when it breaks and you cannot repair it? We had our 20 year old Fan-Tastic Vent Fan and it finally broke.
It could not lift the cover anymore so we decided to get a new vent fan to replace it. After doing plenty of research, we decided to replace it with a new Fan-Tastic RV roof vent with all the bells and whistles.
Measure your old vent fan to make sure you replace it with the correct size vent fan.
To start out, turn the power to the vent fan off at your RV’s circuit breaker. If the power is left on, you could short circuit the line by accident. If your positive wire hits the aluminum frame accidently, you will blow a fuse. Turning off the power will save you from using up a spare fuse.
Remove the trim ring to your RV roof vent fan by unscrewing the four screws on the bottom side. It should then easily slide out.
To keep things clean, I taped a plastic bag sealing the hole from underneath using masking tape.
Use a thin metal putty knife gripped close to the end and score the sealant around the RV vent fan’s mounting edge. Be careful not to cut too deep as to not cut through the RV roof liner.
Use a plastic scraper or panel removal tool to scrape the sealant off of the roof surface against the vent fan mounting edge. I highly recommend using plastic against the roof liner to reduce the possibility of damaging your RV’s roof liner.
The Fan-Tastic Vent Fan that our 5th wheel came with, had the cover’s hinge mounted over the vent fan mounting surface and screws. I unscrewed the cover’s hinge and using the help of my metal putty knife, removed the vent fan cover.
Our 20 year old Fan-Tastic vent fan’s mounting screws were now all exposed. Use a cordless drill to help unscrew each screw. There were a few screws that had been exposed to water and would spin free in the RV roof.
Use a large plastic panel removal tool or scraper to help free the RV roof vent fan from the RV roof. There should be butyl tape holding the vent fan mounting surface to the RV roof. A little pry here and there will help you pull the RV vent fan free.
Clip the wires from the old vent fan and remove it from your work area.
Use your plastic scraper or panel removal tool to scrape as much of the old sealant off the RV roof as possible. It is not very easy but old sealant should be removed before installing the new vent fan. Be very careful not to damage the RV roof liner.
Use a clean rag soaked in rubbing alcohol to wipe 3 to 4 inches of the RV roof surface from the vent fan hole’s edge. I used rubbing alcohol rather than acetone. Acetone is pretty powerful and could turn the RV roof liner gooey podtentially compromising it’s sealing properties.
Because our mounting holes in our 5th wheel roof are 20 years old and show evidence of weather exposure, I used larger gauge screws than the ones that come with the vent fan. So I did not crack the plastic mount of the RV vent fan, I drilled larger pilot holes so the screws could just slide through without restriction. You do not want your pilot holes too big.
You can make the wire connections a few different ways. Use Wire Crimpers and Barrel connectors to make a permanent connection, use male and female connectors for a connection that can be disconnected and reconnected, or use the twist, solder, tape method for a permanent connection. I opted for the twist, solder, tape method.
Strip the positive and negative wires coming from the RV and the new RV roof vent fan. Twist the wire strands of each wire tightly. A tight twist in the multi strand wire is always the best when making 12 volt wire connections. The twisted wires hold better when using connectors and in soldered joints. Criss cross the stripped positive wires and twist each end around the other as tightly as you can.
Use a hot soldering iron pushed against the twisted wire joint to heat the wire. Press some unspooled Rosin core solder into the hot twisted wire so the wire joint soaks up the solder. Use about 3 to 4 inches of electrical tape and wrap the solder joint tight. I used two layers of tape. Repeat for the negative wires.
Prior to the butyl tape, clean the RV roof vent fan mounting surface with a rag soaked in acetone. The acetone will clean any body oils and manufacturing oils from the surface so the butyl tape sticks properly to the plastic mounting surface.
To help make sure you will have a water tight connection between the RV vent fan and your RV roof surface, put 3/4″ butyl tape along the mounting surface of the vent fan.
Press the butyl tape down so it sticks well. Peel the backing off the butyl tape to expose it’s sticky surface. Flip the RV vent fan over so the cover is facing up. Make sure the wires are free and hang down through the hole into your RV as you position the fan over the hole. Make sure the vent opens toward the rear of your RV and slide the vent fan into the hole in your RV roof.
Squeeze sealant/adhesive caulk into each mounting screw hole and a bead around the mount edge where it meets the RV roof to fill any gaps. This is not the final sealing. I highly recommend “Wet Seal”. It works AMAZING on RV roofs. This sealant is self leveling and stays liquid for a couple hours. It was recommended to me by Mark at Sonrise RV in Escondido, CA. I called looking for RV Lap Sealant and they said they have something way better, so I went with the “Wet Seal”.
Prepare the Wet Seal sealant tube by unscrewing the caulking tube tip, cut the tip off of the tube with a razer knife, screw the caulking tip back on, and load the caulking tube into a standard caulking gun.
There is no need to poke a hole through tip, the seal is open when the tip is cut off.
Instead of using the stock screws the new RV vent fan came with, I used a thicker gauge screw to make sure the threads got a good bite on the existing mounting holes. I first had to drill bigger pilot holes in the vent fan mount so the thicker screws would not crack the plastic vent fan mount. I did this step as soon as I removed the vent fan from the box.
Screw each screw into the RV vent fan mount until snug. You do not want to strip the mounting holes.
If using a rain hood, follow the mounting instructions. The mounting hardware that came with the rain hood we chose went on the second to first and last screws on both the driver’s and passenger’s side of the RV vent fan mount. Put a good amount of Wet Seal sealant around the screw hole on the mounting bracket surface that will come in contact with the vent fan mounting surface.
Make sure to fill the screw hole in the vent fan mount with sealant first. Place a screw through the screw hole in the rain hood bracket with the sealant facing down. Place the rain hood bracket sealant side down onto the RV vent fan mount so the screw slides into the empty screw hole. Tighten the screw down so it is snug. Sealant will squeeze out from the edges of the rain hood bracket and screw head.
Squeeze plenty of sealant under the rain hood mounting bracket so the space is completely filled with sealant. This makes a water tight seal.
I really like the idea of having extra protection for the roof vent fan. Not only is this a how to replace your RV roof vent fan but a good idea of what to include with your replacement for longevity of your investment.
Remove the protective plastic from the RV vent fan cover. Place the rain hood over the RV vent fan so the posts on the mounting brackets go through the mounting holes in the rain hood foot’s edge. Make sure the open side of the rain hood faces to the rear of your RV. It is easiest to do one side first and then adjusting the posts in the bracket so the other side will slide onto the posts of each remaining bracket.
Slide a supplied washer onto each mounting post. Then slide a safety clip through each hole in each mounting post.
Go around the edge of the RV vent fan mount with the Wet Seal sealant doing a zig zag motion to lay a 1 inch wide bead of sealant, 1/2 inch over the vent fan mount and 1/2 inch on the RV roof. Cover the screw heads with sealant as well.
You can use your putty knife to softly smooth the top of the sealant bead to make sure there are no air gaps. Be careful no to push down because you do not want to remove any sealant from the RV vent fan mount edge.
Slide the trim ring up through the hole in the ceiling and into the vent fan. Be careful not to pinch the power wires. I used a small square of butyl tape at each corner to hold the trim ring in place. Keep the butyl tape at least 1/8 inch from the edge so it does not squeeze out. Put a screw that came with the vent fan onto your phillips screw driver or cordless drill phillips head bit.
Push the screw into a screw hole in the trim ring, wiggle the screw back and forth until the screw tip finds the existing screw hole and tighten the screw. Repeat for the remaining three screws. Make sure to tighten until snug, do not over tighten. You do not want to crack the plastic trim ring.
Test out your new RV Roof Vent Fan.
That is how to replace your RV roof vent fan.
In order to replace your RV vent fan, you need specific tools. I use these tools for many different RV repair and maintenance jobs. I highly recommend having these tools for your RV roof vent fan replacement.
Fan Tastic RV Roof Vent Fan similar to the one we bought. A roof vent fan with thermostat, automatic temperature setting, manual speed settings, and rain sensor, blow in or out switch, no remote.
Fan Tastic RV Roof Vent Fan three speed settings, no remote
MAXXAIR MaxxFan similar to Fan Tastic Vent Fan. Remote displays: temperature setting + the actual inside temperature, fan on or off, vent open or closed, fan direction. Remote controls: temperature, speed (10 speed settings), on and off. I personally think this fan is a great buy.
Wet Seal Sold at Sonrise RV (760) 745-2444 The best sealant for RV roofs and roof accessories. The guys at Sonrise RV in Escondido CA are incredibly knowledgeable and very helpful. I have been to other RV repair and parts businesses and they do not even begin to compare to Sonrise RV.
Dicor Self-Leveling Lap Sealant, 4 Pack A good alternative to Wet Seal if Wet Seal is unavailable.
3/4″ Butyl Tape Great for creating weather proof junction between panels/mounting surfaces
Auto Trim Removal Tool Set (12 Piece) Great set for scraping, prying, leverage, opening gaps between panels, and removing panels. I love this set. All tools but one are non marring plastic tools.
Makita 18V Hammer Driver-Drill, Impact Driver, Charger, and 5 amp battery with tool bag Great quality 2 speed drill and impact driver with a big 5 amp battery for big jobs.
Electronics soldering iron kit comes with all of the tools needed for electronic soldering work.
Rubbing Alcohol for cleaning oils off RV roof material
Acetone for cleaning oils off mounting surfaces
Barrel Connectors for permanent wire junctions
Male and Female Connectors for disconnectable wire junctions
Channellock Wire Crimping Tool Needed for using connectors