How To Install RV Roof Vent Fan (Replace Fan Blade or Motor)

This is a project that is not meant for beginners or people who do not know what they are doing. While it is a fairly straight forward project, it does require tool skills as well as a lot of patience. These projects do not always work out well even for good handymen.

The first step to install a roof vent is to see how much room you have to work with. Then the second step would be to select the RV vent fan that fits that space. Make sure to take good measurements during the step one phase.

To learn more about installing an RV roof vent fan or its variation, just continue to read our article. It has the information you need to know if you want to take on this project and get more fresh air inside your RV or trailer.

How To Replace an RV Vent Fan


The good news is that half the work is already done when you attempt this project. You do not have to worry about making sure the new housing will fit the opening or how to wire the power to the roof vent fan and other new installation details.

All you are doing is replacing the fan. This can be done in two ways. The first way is to simply remove the fan and fan motor, leaving the housing intact. Then you slip the new fan and motor into the old one’s place.

This option is a matter of removing a few screws and moving the lid or cover out of your way. This smaller project does not take long to do.

The other option is to replace the entire vent van, housing, and all and install a new complete housing and fan set-up. This involves measuring the actual opening and what is called the garnish. The garnish is the trim piece on the inside of your RV giving your ceiling a nice clean look.

Next, you go out and buy a new complete vent package and return. Now is when you remove the old fan, its housing, the garnish, and so on. Don’t forget to unhook the wires and leave them close by but out of the way till you need them.

When that is done, you simply follow the instructions that came with the fan and install the new fan. Don’t forget to hook up those wires to the new fan. When the fan is in place, make sure to seal the roof side of the installation to prevent any leaks.

How do I Know What RV Vent Fan To Get

The answer to this question is that the majority of your decision will be up to your preference. But there are other factors involved as well. Here is a short list of those factors

1. Brand- choose a brand you trust and there are many companies making roof vent fans for RVs. Dometic, Camco, Fan-Tastic, Livpow, Maxxair, Ventline, Heng’s, Hike Crew, and Vortex are just some of those brands

2. Price- there are many different types of fans out there that have a lot of extra features or none at all. It will be your preference that makes this decision but make sure it fits your budget.

3. Features- some are entirely manually operated while others are electronic and use remote controls. Then there will be a variety of models with different speed levels. Pick the one with the features you want. Nothing wrong with going old school and picking a non-electric, hand-operated vent fan.

4. Ease of use & installation- you do not want a vent fan that is hard to operate or install. Remember remotes need batteries so that will be an added expense later on down the road.

How To Remove an RV Roof Vent Fan

The first step in this process will be to remove the interior trim piece. That should be held in place by up to 4 screws. When you remove that you need to shut the power off to the fan.

Then disconnect the wires to the old fan once you return from cutting the power. After this step, it is time to move to the roof and get ready to remove the sealant. You can cut away the sealant if it is not lap sealant. But if it is, you should use a heat gun to soften it up so it can be peeled away.

Just watch out for the heat as the sealant can and will get hot. When that part of this task is done, scrape away any sealant that covers the flange and the screw heads. Once you see the screw heads, start removing them.

You can remove the cover and the lid at this time and then move on to removing the fan and motor. This is all a matter of removing the screws that hold each part in place.

That work makes removing the flange a lot easier. Sometimes the flange is held down by Butyl tape so use a putty knife to separate the flange from the roof and the tape.

After removing the flange, make sure all the wires are disconnected and ready for when you install the new roof vent fan.

How To Install an RV Roof Vent Fan


Depending on the type of roof vent fan you are installing, here is a list of tools you will and may need- Ladder, Screws, Screwdriver, Phillips head screwdriver, Needle-nose pliers, Putty Knife, Drill, and drill bits, Butyl tape, Dicor Lap Sealant & caulk gun, a measuring tape.

The first step would be to use denatured alcohol or similar products, to clean and remove the old sealant from the rooftop around the fan opening.

Step two- cover any old screw holes with butyl tape and that helps provide a good seal when you are done.

Step three- put the new fan in the opening and put the new screws in to hold the fan. You want the screws tight but not over-tight. If you over-tighten the screws you may strip the hold and have to drill new holes for the screws.

Side note- make sure the wires are in place before you insert the fan. Then connect the wires to the new fan before you move on to the next step.

Step four- Once that is done and the fan is secure, seal the exterior of the fan thoroughly. Do not leave any gaps, holes, or anything that will allow the water to enter.

Step five- When that is done, install your lid, cover arms, vent cover ad other parts the exterior needs and you should be done.

How To Wire an RV Vent Fan

If you are merely replacing an old fan, the wiring will already be in place. That saves you a ton of work routing the wires to the correct power source. All you have to do is hook up the existing wires to the right terminals or connections and you are done.

If you are not an electrician or have electrical skills or experience, do not do the new wiring yourself. There is a lot of work involved in running the wires from the fan to the power source

There are two options you can choose to use. The first option is to wire the ceiling vent fan to the nearest light fixture. The drawback to that option is that you may have to turn the light on to use the fan.

That is the simplest and quickest method to use. The other method would be to run the wire directly to the battery or into the same circuit breaker your lights use. This option is more work but it allows you to use the fan with the lights off.

Installation is just a matter of running the wires to the power source you have chosen, then making the right connections. Wiring is actually very straight forward. The hard part is to find the best routes and then make secure connections.

Do not forget to shut the power off when you are making those connections. When you are installing a new fan with new wiring and routes, the only time you need to shut the power off is when you are connecting those wires to the power source. When using the original wires from the old fan, shut the power off before connecting the wires to the fan.

Replacing an RV Vent Fan Blade

This is probably more work than replacing the complete fan and the motor. You have to do the same amount of work to get to the fan blade as you would removing the old fan.

There is no other option as you have to remove the fan to get to the screws holding the fan blade in place. The model of the vent fan will determine how much work you have to do.

The first step would be to shut the power off as you do not want any accidental starts while you are removing or adding the fan blade. The second step would be to remove the interior screen.

After that, you need to climb onto the roof and remove the cover and the fan motor. The fan blades may be held in place by an Allan wrench screw so bring those along with you.

All you need to do once you get to the fan motor is to loosen, not remove, the Allan wrench screw. That will allow you to pull the damaged blade off and install the new one. Once the new one is in place, tighten that screw again.

Then reverse your steps and put the fan back together. The fan blade is a simple part to replace but the work involved is more effort than you would like to do.

How To Replace The RV Vent Fan Motor


Every removal and installation instruction we have mentioned already will apply to this project. It takes as much, if not more work to remove the fan motor than simply replacing the fan or fan blade.

The reason we say that is that you will have to add in the extra step of separating the motor from the fan. Then attaching the fan to the new motor. Make sure the power is off before you start this work.

Then remove the interior screen, and move on up to the roof to do the hard work. Remove the cover and you should loosen or remove those cover arms to give you more room to work.

Once those are off, you can either remove the wires from the motor or remove the motor and then the wires. This will depend on which type of fan unit you have on your roof.

Once you disconnect the wires from the motor and remove the screws, the fan motor should slip out. Next, you simply reverse those steps to install the new motor. After the motor is back in place, reinstall the cover and cover arms.

Now climb back down off the roof, go inside and replace the screen and turn the power back on. After every installation or repair, make sure to do a test to see that you got the installation right.

How To Add a Fan To an Existing RV Vent

The key here would be to do accurate measuring. You will want your new roof vent fan to fit exactly into the opening so that there are no gaps and no need to exp[and that opening.

To do that you need to take good measurements. The next step will be to take those measurements with you and look for a ceiling fan assembly that will fit into that opening.

The standard opening for RV roof vents is supposed to be 14 by 14 inches. Double-check to make sure that is true for your RV or trailer. Since companies make RV roof vent fans, those models should fit that standard.

Just because there is a standard size does it mean all fans and vent openings are made to that standard? After you get the right-sized vent fan, it is a matter of routing the wire to the power source you want to use.

Then installing the new fan unit. The hardest part will be routing those wires as the vent assembly should easily screw into the roof of your RV, etc. When the vent fan is in place, seal it up completely. That cannot be emphasized enough.

You do not have to use the old vent cover or lid or any of its assembly. You can simply remove all those and buy a vent fan that comes with those items. Remember to shut the power off when you are ready to connect to the power source you have chosen to use.

The Bathroom Fan Vent in The RV Leaks Water

The most common source for this problem is that someone did not seal the bathroom vent very well. It happens as RV makers are in a hurry to get their models built and out to their customers.

You will have to go up on the roof and check the sealant. If there are holes you can clean out the old sealant and redo the work which is a good option due to silicone’s adhesive restrictions.

There are lots of sealant options to choose from though and pick the one that is best for you. Now, this could be a simple problem of forgetfulness as well. Someone may have forgotten to shut the cover or did not close it all the way when the rain started.

Before you do all that work, check to see if the cover is fully closed. The drawback to these solutions is that the water leak may come from another location so while you are on the roof, check all your seals to make sure they are not leaking. Oh and before we forget, damage to your roof could have broken the sealant and not be a manufacturer’s error.

Why Doesn't My RV Bathroom Vent Fan Work?


There are many reasons for this situation and most are simple common sense problems. First, the fuse may have blown if there is a fuse to this device. Second, the breaker may have tripped cutting off the power.

Third, the battery lost power. Fourth, the batteries in the remote lost power. Fifth, you forgot to turn the light on when you entered the room. These are simple to repair.

Those are the simplest problems so check your power sources first before moving to the next possible sources. Those possible sources include, you wired the vent fan wrong or the switch is broken., or there is a loose wire, connection, or damage to both.

These problems take a multimeter and a little more work to diagnose. Finally, the fan may be bad, the fan blades may be dirty or the motor failed in some way and needs to be replaced.

If the source is one of those problems, then you will have to get up on the roof to clean the blades, replace the motor or repair the wires and connections. If the fan or motor is bad and you haven’t owned it for long, then you may be able to get a replacement and do the installation work again.

What Size Is an RV Vent Fan Crank

The size will depend on the design of the vent fan assembly. Some units only come with a round knob that you grasp and turn. The knob has 4 spots that extend from the center to wrap your fingers around and turn like you would a screw.

Another crank design measures 6 inches in length and it looks like a straight metal rod attached to a cranking mechanism. Probably the most common design will be a crank that looks like those old-time window cranks many traditional houses had before sliding windows were used.

Those may be 4 to 6 inches in length and have a couple of angles to them for easier cranking. Those seem to be the three most common types of hand cranks RV roof vent makers use to move their manually operated covers up and down.

You are not going to get a lot of reach with these cranks and you may need a step stool to reach them if you are shorter than average. They may not turn that fast either. If you are going manual, make sure to check this vital part out and select the best option for your RV situation.

DIY RV Vent Fan

Unless you are buying all the components separately and assembling them yourself there is no DIY vent fan model you can buy. The DIY part will be in doing the work yourself using a pre-made fan assembly.

If you are starting from scratch and putting in a new fan, you will need to buy the fan assembly, wires, wire connectors, and silicone. The tools you will need will be a drill, jigsaw, drill bits, and screws.

Then you cut the hole yourself and install the fan per the instructions given already. This is a project for those who know what they are doing. The wiring will be the hardest part and you should have a professional electrician make the connection to the power source to protect your insurance and warranty.

Insurance companies frown on DIY electricians and you could void any warranty protection you may have by making the wrong connection.

Some Additional Words

Installing an RV roof vent fan is not the most complicated project you can undertake. It is fairly straight forward and you can use pre-existing vents to install the powered fan.

The hardest part is the wiring but what is next in line is making all the decisions that come with buying a fan set, where to install it and where will you run the wires if necessary.

If you are unsure about this project or do not have the experience get an experienced person to help you.

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