[firstlight]

2006 36 ft. Open when I fill water tank it over fills and pushes floor board up in bilge. Water does vent out over flow but not enough to prevent tank from OVER expanding. Thanks Frank

[Uhehner]

Use a dental pick to remove the screens from the overboard vent. They corrode shut with time and are only needed on fuel tank vents. I took the screens out of the waste tank vent also. Hope this helps. Capt. George

[Chris Burkard]

Yes, your vent is likely clogged. I like the idea of the screens to keep the critters out, but to each his own. You could try cleaning it instead of removing. Good luck!

Tip: Do not overflow the holding tank. If you do, you will have to replace the charcoal filter located on the vent line.