The Black Water Tank On My RV Will Not Drain

by Greg Sherman
(Anacortes, WA)

I have an 18 foot Coachman Catalina Travel Trailer. The black water tank doesn't drain, meaning I have to siphon it out every 3-4 days. Does anybody have any ideas what the problem might be and what options there are for repair?

ANSWER: Greetings Greg thanks for submitting your question on our Ask An RV Question Page.

With the information you have provided me I really cannot tell you the exact problem with your Black Water Holding Tank. If it is because the Holding Tank Dump Valve is not opening and closing, you will probably end up having to replace the Dump Valve.

In some cases the holding tank itself could have a blockage in it. Sometimes using Holding Tank Waste Digesters can clear up the blockage. If all else fails, you may have to take the trailer in and have the holding tank dropped and cleaned out manually.

We have all kinds of information on holding tank care and maintenance on our website you might want to review the answers I gave to the questions listed below to get further information.

Leave your RV repair bills to us—Good Sam Extended Service Plan

The Black Water Holding Tank Valve On Our RV Is Stuck Closed 

RV Tips for Holding Tanks

How Do I Flush The Gray and Black Water Holding Tanks on a 2006 Keystone Hobbi?

What Can We Do To Keep Our RVs Black Water Holding Tank From Clogging Up?

Hopefully I have provided you enough information to help you resolve your holding tank problem

Do you have any suggestions or comments on this topic? You can add them to this page by clicking on the "Click Here To Post Comments" link located near the bottom of this page.

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Happy RVing

RVing Al

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Having Similar Problem
by: Anonymous

I am having similar issue with my '94 Fleetwood Terry Fifth Wheel. I dumped my black water tank the day before Christmas. Since it takes roughly 30 minutes to fully drain, I decided to get everything ready for Christmas at a friend's house since I would be gone for a couple of days. However, I forgot to close before leaving for my friend's house. The sensor shows that the tank is only 1/3 full, but the black water will not drain from my toilet at all. I do not know if the waste froze over the week that the black water tank valve was open or if it is just a clog. Any advise?

Black Water tank not draining
by: Anonymous

I had a similar issue with my gray water. One day I decided to fix it or tare it up so I took the drain system apart and found that when they drilled hole in the tank at the factory they let the drilled out plastic fall into the tank and it work its way into the fiiting. Once I removed it, the tank drained fine.

cleaning tool
by: Bill

first turn off water going into rv,turn off pump hold open flush valve with a wood stick,break off a paint stir stick to fit.look down hole in toilet with flashlight if full .it is probably plugged with tissue,buy a cleaning tool at local hardware attaches to garden hose and has a on off valve,stick it down hole turn water on and it should clean out and breake loose any thing stuck.

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