Toilet works: slow flushing toilet

September 15, 2008 2:42 PM

My toilet is flushing slowly. Sometimes it takes 3+ flushes to completely remove waste. I have completely replaced all of the internals, and tried the CLR method. I have even manually cleared out the return / fill holes. It has helped some, but not enough. I think I need to use something stronger than CLR, like muriatic acid. The problem is I am on a septic tank and everything I read says do not use the muriatic acid method if you are on septic as it will kill all of the beneficial bacteria in the septic tank. So, my thoughts are to use the muriatic acid to clean out the bowl, but before the first flush, use baking soda to neutralize the acid as much as possible. Then flush. After about a week, add some RidX to help restore some of the lost bacteria and after another week or so, add another box of RidX. Is this a sound plan or should I abandon the muriatic acid idea completely?
posted by twistedmetal to Home & Garden (17 answers total)

If you mix hydrochloric acid and baking soda, it'll foam all over the place. Think "vinegar+baking soda" and multiply by 10, with the foam being able to cause first or second degree burns on your skin if it hasn't yet been totally neutralized.

DEFINITELY not a good idea.
posted by Class Goat at 2:47 PM on September 15, 2008

How's the water pressure where you are? Slow flushes can be caused by low pressure.
posted by chrisfromthelc at 2:56 PM on September 15, 2008

If the toilet is old (e.g. older than 10 years), it might not be engineered as well as some of the newer models (in terms of flushing power, size of output tube, etc. -- obviously I'm not a plumber).

However, you might want to invest in a new toilet if the existing model is older. I did that, and now have a 1-flush system. Pretty cool. I got the Cadet 3 for around $125 at HD.
posted by noahv at 3:09 PM on September 15, 2008

Have you used the root killer products? It may be flushing slowly because of a blockage of roots in your healthy septic tank.
posted by parilous at 3:23 PM on September 15, 2008 [1 favorite]

It sounds to me like it might not be vented properly. If air can't get into the drainpipe fast enough the water won't drain out of the bowl at the proper speed. You could check to see if the vent stack is clogged by going up on the roof and lowering something heavy on a string down the pipe.

If it never, ever really drained at a good speed, then it might be a DIY installation that will require having a vent line put in by a plumber (but this will involve opening up the wall and the floor). However, if it's less than 3 feet from the main vent stack, I don't think venting is an issue (but I'm not a plumber).

I'd try a new toilet first though.
posted by bonobothegreat at 3:30 PM on September 15, 2008

Have you had someone out to assess the health of your septic tank? We had a tank that was basically collapsing and causing all kinds of flushing/drainage issues. The guy had a little fiber optic camera on a cord that could travel the whole length of the plumbing from the toilet to the tank to diagnose issues.
posted by Rock Steady at 3:46 PM on September 15, 2008 [1 favorite]

Response by poster: Water pressure is good.
The other three toilets flush ok, so that's why I think it's just this particular toilet/vent and not the septic system.
I have thought about checking the vent line, but I wanted to exhaust other opportunities first. I hate heights.
posted by twistedmetal at 3:57 PM on September 15, 2008

Chiming in in support of bonobothegreat - a venting problem sounds very plausible. That said, it could easily be that the toilet is poorly designed. Some of the early water-saver toilets never worked well even when the installation was fine and they were brand new. I replaced one of those lemons with a Kohler Wellworth three years ago, and it has performed very well.
posted by jon1270 at 4:01 PM on September 15, 2008

Different toilets flush differently. I have seen some newer toilets that are more water efficient and flush with a vengeance. See power flush toilets.
posted by JJ86 at 4:02 PM on September 15, 2008

We had a tree root problem with our septic system, and at first only one toilet seemed to be affected, only later did the others flush noticeably slower. Roots just keep getting worse until they totally block things and you have a huge mess, so it would be good to check for roots -- if you have an easily accesible cover to your tank, you can find out pretty easily. Good luck.
posted by mmf at 4:19 PM on September 15, 2008

Check the tank and see how high up the water gets before stopping refilling. You can adjust the float higher to give you more water and force during the flush.
posted by rhizome at 4:29 PM on September 15, 2008 [1 favorite]

Acid will only clean off mineral deposits in the bowl etc. It won't clear out the line to any meaningful degree unless you use something that's just ridiculously (dangerously) strong. If the usual basics didn't fix it hire someone.
posted by aramaic at 4:42 PM on September 15, 2008

...dangit, I neglected to say: if you insist on using acid then here is a semi-reasonable explanation of the technique. It seems to roughly mirror the method I once saw used, but note that I have not actually performed this myself so it may be tragically wrong.
posted by aramaic at 4:47 PM on September 15, 2008

Another vote for probable root infiltration or dead birds down the vent or other gross blockage, none of which the acid will do squat for. Before playing with any more nasty chemicals, pay somebody to run a roto-rooter down the drain and a wire down the vent stack and see what gets dredged up.
posted by flabdablet at 6:09 PM on September 15, 2008

Toilets are easy to remove (two bolts and a water connection). If you want to do the acid thing you could remove the toilet and do it in your driveway, fill the tank with a hose or bucket, or something and thereby avoid dumping the acid in the tank. You'd need a new wax seal (a couple bucks) when you replace the toilet.
posted by Mitheral at 6:32 PM on September 15, 2008

You might have an incomplete siphon. If the siphon is not properly getting primed with the amount of water in your tank, it would produce this result.

To test this, get a bucket full of water (much more water than is stored in your tank). Dump it very quickly into the bowl, attempthing to fill the bowl as high as possible; you may want to put some towels around and wear clothes that can get wet. If it flushes correctly your siphon is the problem.
posted by warriorengineer at 8:14 AM on September 16, 2008

Response by poster: @ warriorengineer

And what is the fix for this? Is it a blockage in the vent?
posted by twistedmetal at 10:10 AM on September 16, 2008