MaxxFan products are awesome. Make no mistake. That’s why we have two of them installed in our van. They run quiet, use little power, and move plenty of air. The MaxxAir MaxxFan Deluxe in particular is a great unit because it comes with the attached weather protection cover.

Sprinter van conversion guide

But there’s a serious flaw in the design and product quality of these fans. Yes, even including the “weatherproof” Deluxe models!

This issue is that the printed circuit board (PCB) and keypad which allow the fan to operate are not adequately protected from moisture and the environment.

This means that if you are using your MaxxFan in just about any climate, other than dry arid climates, there is a risk that the fan will eventually fail due to condensation on the inside of the lid, exposure to high humidity, or small splatters droplets coming inside the fan hood on heavy downpours.

What went wrong with our Maxxfan?

A couple of months ago we had a unexpected and heavy downpour of rain at 3am. We received about 95mm within a couple of hours, and for the next 24 hours we had 90%+ humidity too. 

That morning we woke to our MaxxFan Deluxe over our bedroom beeping and turning itself off and on constantly. We pulled the fuse and left it be to dry out for a while.

A few days later we re-connected it to power, and it seemed like it was all good again. However the next night it started to trip out and turn it self off and on again. Knowing that we needed to find a solution, we jumped on to YouTube and on some vanlife themed Facebook groups, did some searches, and these results confirmed our fears – the PCB and/or the keypad had gotten wet and would probably need to be replaced.

So it turns out that the PCB used in all MaxxFan models, despite being destined for use in harsh environments, are not covered with any form of moisture protection or conformal coating.

Why AirXcel (the company that owns and manufactures MaxxAir products) decided to save literally cents on each unit and not have the PCB coated from the factory is beyond us.

How to fix this?

The good news for the consumers is that you can easily and inexpensively remove the PCB yourself, even with the fan installed, and coat the PCB with  conformal coating to help protect it from moisture and other elements. 

All you’ll need is the conformal coating spray, a phillips head screwdriver, plus maybe some pliers and side cutters if you didn’t use quick connect cable joiners when you originally installed the fan.

First you’ll need to remove the mesh bug screen on your Maxxfan. Then use the screwdriver to undo and remove the four screws that were covered by the circle attached to the mesh.

You’ll also need to remove the opening knob handle using the screwdriver if you have the manual opening option. These screws you’ll need to undo are shown in the below photo with red circles.

MaxxAir MaxxFan

Then you’ll have access to the PCB. Simply snip the cable ties holding the cables together, lower it all down, then unplug the keypad and other plugs from the PCB.

Undo the three screws that attach the PCB to the plastic mounting plate, ensuring that you don’t lose any of the nylon washers they have used – you’ll need all that to reassemble.

Using conformal coating

After you have freed the PCB from the housing,the first thing you want to do is use some making tape and/or putty to cover up the connections and communications ports. Conformal coating is non-conductive, so you don’t want it clogging up the connections and preventing the PCB from working.

You are now ready to apply the conformal spray, which is also known as “acrylic protective lacquer”.It’s great stuff, and a small can of it is worth adding to your kit of electrical tools.

Note: Conformal coating comes in all sorts of different variations. We aren’t electrical engineers and can’t advise which option is the best. We did ask the electronics store where we bought ours from, and they were adamant that the cheap and simple acrylic version was perfect for what we needed. It was about $25 AUD including express postage. Click here for the link to the exact conformal coating we used if you’re interested.

We put three coats of the conformal coating on each PCB, allowing 30-40 minutes to cure between coats. We are lucky enough to be in the far north of Australia right now, where winter consists of warm and dry conditions. Obviously, you will need to allow extra time for curing if you are somewhere less warm and dry.

Final steps

If you can get a source for it, you might also want to consider getting some moisture repelling dielectric grease and putting a small bead around the back of the keypad where the ribbon connects. Since the keypad is pretty cheap, we didn’t bother with it ourself.

After everything is coated evenly and cured, you’re ready to reverse the process. Rip off the masking tape, reinstall the PCB, stick it back up into the main fan housing, and you’re done. Ready to drive off into the sunset knowing that with a small amount of time and money you have helped to protect hundreds of dollars worth of electronics.

Easy done! Hope this helped!

As a side note..

The part numbers are 10-21299KI for the keypad (RRP $5 plus postage) and 10-21277K for the PCB (RRP AU $125 plus postage) if you need to buy a replacement.

Send us an email if you’re interested! We can ship to you anywhere within Australia.

Shout out to the Everlanders channel for posting a video on the same topic, check them out.