bsjones11 Report post Posted January 20, 2019 My bathroom sink will sometimes hold water as if it is stopped up. Sometimes drains quickly. I have taken apart pipes to sink and trap and find nothing. I have used drain cleaner and all flows fine. But sometimes especially in morning it will hold water just as if clogged. Any suggestions??? Share this post Link to post Share on other sites
desertdeals69 Report post Posted January 20, 2019 Check the roof vent on the gray tank. Share this post Link to post Share on other sites
bosun Report post Posted January 20, 2019 Greetings! Interesting problem. I wonder if maybe your vent is clogged? Long shot, but worth looking at. Good luck! Share this post Link to post Share on other sites
richard5933 Report post Posted January 21, 2019 Are you in a cold climate? Since you say it's worse in the morning I'm wondering if you have frost building up in the vent cap overnight. Share this post Link to post Share on other sites
campcop Report post Posted January 26, 2019 Don’t know what kind of MH you have. It would help if you posted that. On ours, under the sink, in the cabinet there is an AAV, if you have one, it could be defective and sticking at times. Share this post Link to post Share on other sites