Black Holding Tank slow to drain...
Our Black Holding Tank is slow to drain. Can this be caused by a bad Air Admittance Valve or a clogged vent cap or both? The tank dumps fine at first, but it eventually backs up and then very slowly...
Forum Discussion
Thanks for all the replies, I should have been more clear. The problem isn't the tank. The waste drains quickly at first, but then as the sewer hose fills up, it slows down considerably. It will eventually drain after a minute or two. Once the hose is empty, I can turn the black tank rinser on and it flows without a problem.
I guess it could be a problem with the septic, each site has its own, but I don't have a problem draining the grey tank. When the black tank rinser is going, I can leave it on for 10+ minutes and it never backs up.
It seems like when the sewer hose gets full, the waste just moves through it much slower. The grey tank is only a 2" pipe, so the liquid doesn't move through the hose as quick and can't build up.
I did have my wife flush the toilet and keep it open for about a minute and it did not help the flow, but it was already backed up at that point. Today, I flushed the tank when it was only about 1/4 full and it drained no problem. I ran the black tank rinser for about 10 minutes with the valve open and it drained fine. I closed the valve and let it fill up about 1/4 full again and opened the valve, no back up.
Now that I've written it all down, it makes me believe maybe it is the septic. Perhaps it is having trouble keeping up when dumping a full black tank.
-Michael
I guess it could be a problem with the septic, each site has its own, but I don't have a problem draining the grey tank. When the black tank rinser is going, I can leave it on for 10+ minutes and it never backs up.
It seems like when the sewer hose gets full, the waste just moves through it much slower. The grey tank is only a 2" pipe, so the liquid doesn't move through the hose as quick and can't build up.
I did have my wife flush the toilet and keep it open for about a minute and it did not help the flow, but it was already backed up at that point. Today, I flushed the tank when it was only about 1/4 full and it drained no problem. I ran the black tank rinser for about 10 minutes with the valve open and it drained fine. I closed the valve and let it fill up about 1/4 full again and opened the valve, no back up.
Now that I've written it all down, it makes me believe maybe it is the septic. Perhaps it is having trouble keeping up when dumping a full black tank.
-Michael
