Vinegar is like a magic potion that you can use to get rid of stains, rust and hard water deposits, and it tastes great on salad and French fries, too. Its miraculous powers and tart, tangy flavor come from the acetic acid it contains, and as far as acids go, acetic acid is fairly strong. By itself, though, vinegar probably isn't strong enough to bust a stubborn drain clog.
How about if you mix it with boiling water and combine its dissolving power with the emulsifying power of heat? If you have a slow drain, the combination may help debris in the pipes move along and improve water flow, but the combination probably won't clear a clogged drainpipe that's completely stopped. If the pipes are plastic, it could make matters worse because boiling water can melt plastic.
Using Boiling Water to Clear a Drain Is an Old Remedy
Some plumbers recommend boiling water as a first-stage drain cleaner to be used before you resort to chemicals or mechanical drain cleaning methods. Because it has to come in direct contact with the clog to do its thing, boiling water works best when the drain is still flowing, and it doesn't work as well when it's diluted by standing water in the sink. The same is true if you're trying to unclog a drain with salt.
Vinegar doesn't improve matters much. The concentration of acetic acid in vinegar is already low, which is why you can use vinegar as a condiment, and adding it to water reduces the concentration even more. It won't hurt anything to try it, though, and you may be one of the rare people who finds that pouring a combination of vinegar and boiling water down a bathtub drain can actually work sometimes.
Using vinegar and boiling water as a drain cleaner is a bit like using vinegar to remove cured silicone caulk. Vinegar can't dissolve silicone, but it can make it softer and easier to scrape off. In the same way, vinegar and boiling water can soften a drain clog and make it easier to remove by plunging.
Add Baking Soda for More Cleaning Power
Combining baking soda and vinegar is generally ineffective for cleaning stains because acidic vinegar and alkaline baking soda neutralize each other. However, the combination does create carbon dioxide foam, and that can help loosen debris in pipes so that the boiling water can wash it away. The foam is fun to watch, and it can't hurt anything, so there's no reason not to give it a try using a procedure similar to the following:
- Bring a gallon of water to a rolling boil on the stove, then pour in a cup of white distilled vinegar.
- Pour 1/2 cup of baking soda into the drain and follow that with a half gallon of the mixture of water and vinegar. The mixture will begin foaming, and the foam should come spurting out of the drain and cover the bottom of the sink or bathtub.
- Wait for the foaming to stop, then pour in the rest of the water.
- Turn on the hot water and let it run for a minute or so. if you don't see an improvement in drain flow, try the treatment again. If it doesn't work a second time, it's time for more drastic measures.
Getting Serious About Clearing a Clogged Drain Pipe
The foam was fun, but if it didn't work, it's now time to get down to business. Here are a few strategies that are more likely to get the job done:
- Use a commercial drain cleaner, but only if you're not on a septic system and the sink doesn't have a garbage disposal.
- Plunge the drain with a sink plunger.
- Disassemble the P-trap and clean it.
- Use a snake to clear clogs from the P-trap or waste line after you've removed the P-trap.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.