Last year we got hit with a hail storm that took out our slide toppers, shower skylight and two of the three roof vent fans (Kitchen & half bath).
I replaced the slide toppers with upgraded material from tough top awnings and the shower skylight from RecPro. Finding just the vent fan lid was bit more work. Our 2020 39FBB came with the Dometic (Fantastic Fan) model FV4100 and eventually found the replacement lids at Home Depot online for about $50 each. I purchased three to keep one as a spare just in case. I replaced the two that were shattered and broken and they quickly broke again after only a few uses.
Both broke in the same location, the metal bracket that attaches to the lift arm to raise and lower the lid. Dometic did a poor job of designing these and the stress put on the plastic and the small screw holding it in place caused it to quickly break. Not wanting to purchase another set of lids or upgrade to a different fan, I just sealed the two broken fans shut. Dometic has discontinued the FV4100 model, but does have similar replacements available.
I decided to revisit them this week and replaced the kitchen lid with the remaining spare I had on hand. It broke again in the same spot after just two cycles of opening and closing. I was close to pulling the trigger on spending close to $800 on a pair of MaxxAir fans as they seemed a better option than the more expensive (and less featured) Dometic fans.
While researching this problem I found this seems to be a common occurrence and I came across a video that shows how a Tiffin owner decided to better secure the bracket to the lid.
Fixing Fan-Tastic Fan broken vent lid part # K1020
I decided to give that a try as it only cost about $5 for the hardware. I used an 11/64" bit to drill the hole and #8-32 1" machine screw and matching nut (didn’t need to the spacer/standoff).
The finished product with the fix in place.
Exterior
Bracket side
Can’t speak to the longevity of this cheap fix, but it’s already cycled the vent lids more times than the stock ones ever did. Not a bad option if you don’t want to spend hundreds of dollars to replace.