Why is My MaxxFan Plus 4-Speed Roof Vent Only Opening About an Inch?

Updated 04/18/2025 | Published 04/15/2025

Question:

Problem with MaxxAir AirExcel 4-speed RV roof fan. Only opens about 1 inch. This has an auto-rain closure. All speeds work, The fan will not open up unless I manually crank. What would cause this problem? Thank you.

asked by: Jeff

Expert Reply:

Hello Jeff,

It sounds like your MaxxAir AirExcel 4-speed roof fan # MA00-04751KSX is having a bit of trouble with the lid only opening about an inch, even though the fan itself works on all speeds. Since it does open when you manually crank it, that’s actually a helpful clue. One of the most common causes is a weak or jammed lift motor. These motors can wear out over time or get a little sticky, especially if the fan hasn’t been used regularly. Sometimes, if you give the lid a gentle manual push and then turn it on, the motor might kick in and finish the job, that’s a sign it’s getting power but just doesn’t have enough strength anymore.

Another possibility is the rain sensor. These fans have an automatic closing feature when they detect rain, but if the sensor is dirty, damp, or just malfunctioning, it might be telling the fan to stay closed even when it’s dry. You can try cleaning the little metal plate on the sensor with rubbing alcohol and a soft cloth. If that doesn’t work, you could unplug the sensor from the circuit board temporarily just to see if the fan starts behaving normally without it.

There’s also a chance the issue lies with a limit switch or the control board itself. If a limit switch is out of alignment, it might be falsely signaling that the lid is already fully open, which would stop the motor early. And if the control board isn’t sending enough power to the lift motor, the fan might act like this too. A visual inspection of the wiring and switches under the fan's cover can sometimes reveal what’s going on.

If you check these things and are still having issues please let me know. Also, how long have you had the fan? Is it new?

expert reply by: Kate F