The short answer
Used once in a while on a slow drain, Drano won’t ruin the plastic drain pipe in most Northern Virginia homes. The trouble starts when it’s poured on a drain that’s fully stopped, or poured again and again. It rarely clears a full clog, it sits in the pipe for hours instead, and on older metal drains it speeds up wear that’s already under way. A plunger, a cable or a trip to the P-trap clears more clogs, and leaves nothing caustic behind.
What’s in it, and how it works
Most Drano products are built on lye (sodium hydroxide), and the gels add bleach. Lye turns grease into a kind of soap and breaks down hair and paper, and the reaction makes heat. On a slow drain with a thin coat of grease and hair, that can open it back up. The product has to reach the clog to work, though, and it’s heavier than water, which is why the gels sink through standing water. On a drain that’s fully stopped it can only work on the face of the clog, and the rest of the bottle waits in the trap.
$99 Drain Clearing
This offer focuses on clearing a blockage up to the P-trap, the curved section of drainpipe beneath the sink where debris can collect. See the drain clearing
Where it does harm
Swipe to see all columns →
Swipe to see all columns →
| Situation | What happens |
|---|---|
| A full clog | It sits in the trap and the pipe for hours, and usually the drain is still stopped when you come back. |
| Galvanized steel drains | Lye strips the zinc coating that keeps the steel from rusting, and these pipes are already rusting from the inside. |
| Old cast iron | The bleach in the gels is hard on metal, and cast iron that’s thin from decades of use doesn’t need help. Cast iron splits along its length when it goes. |
| Plastic (PVC) drains | Holds up at the label dose. Heavy, repeated use is what to avoid. |
| A toilet | The bowl holds it against the porcelain, and a clogged toilet can’t drain it. |
A lot of Northern Virginia houses built before the 1970s still have some galvanized or cast iron drain line inside, usually the stack and the branch lines in the basement. If yours is one of them, a bottle every few weeks isn’t saving you a service call. It’s moving it closer.
The part nobody mentions: the next person
When a chemical cleaner doesn’t clear the clog, the drain is now full of lye. Plunging it splashes that on your skin and in your eyes. Taking the trap apart pours it on your hands. That’s true for you and for the plumber, so if you’ve poured something in, say so before anyone opens the pipe, with the product name and roughly when.
Never follow one drain cleaner with a different one. Mixing a lye cleaner with an acid cleaner can boil up out of the drain, and bleach mixed with ammonia or acid makes a toxic gas. If one bottle didn’t work, the next step is a tool, not a second bottle.
What works better
- A sink: pull the stopper and clean it, then use a cup plunger with a wet rag over the overflow. Still slow? Take the trap off and clean it. How to unclog a sink drain and what a P-trap is walk through both.
- A bathroom sink that drains slowly: it’s almost always the stopper. Bathroom sink draining slowly.
- A shower or tub: it’s hair, and hair has to come out by hand. How to unclog a shower drain.
- A toilet: a flange plunger, then a toilet auger. How to unclog a toilet.
- A clog past the trap: a hand snake. How to use a drain snake.
For keeping a drain clear, as opposed to clearing a clog, an enzyme drain cleaner used on a schedule is gentle on pipes. It works slowly, over days, and won’t open a stopped drain. Baking soda and vinegar fizz nicely, but most of that reaction is spent in the first few inches of pipe.
When to stop
One pour that didn’t work is the signal. So is more than one drain slow at once, or water coming up in a tub or floor drain, because that’s a clog in the main line, and nothing poured in a sink reaches it. One drain or the main line covers how to tell. Kitchen drains that clog every few months have grease coating the pipe wall, and a water jetter scours it off where a cable or a chemical only opens a hole. The holidays are when those lines give out: holiday kitchen drain clogs.
When you’d rather we do it
A sink clogged at the trap is $99 with our sink clearing offer, up to the P-trap. A toilet, tub, shower or any drain past the trap is drain cleaning, $200 to $800. The main line to the street runs $550 to $1,650, and when grease or roots keep coming back, hydro jetting clears the pipe wall. You get the price before we start. A plumbing diagnosis visit is $49, or $250 after hours.
Call (703) 997-9757, day or night, or see every current deal on our offers page. Rated 5.0 stars across 1,138 reviews on Google, Angi, Yelp, the BBB and Facebook, Virginia Class A license 2705192276.
Questions people ask
Is Drano bad for pipes?
Once in a while on a slow drain in plastic pipe, rarely. On a full clog it sits in the pipe instead of clearing it, and on old galvanized or cast iron drains the lye and bleach speed up wear already under way.
Can you use Drano in a toilet?
We wouldn’t. A clogged toilet holds it in the bowl against the porcelain, and if it doesn’t work, the next person plunging is splashing it. Use a flange plunger, then a toilet auger.
What should I do if Drano didn’t work?
Stop there. Don’t pour a second product, which can react with the first, and don’t plunge, which splashes it. Tell whoever comes what you used and when.
Does baking soda and vinegar unclog a drain?
It fizzes, but most of the reaction is spent before it reaches the clog. It can freshen a slow drain. It won’t clear a real clog.
What do plumbers use instead of Drano?
A cable, the drain snake, for most clogs, and a water jetter for grease and roots. Both take the clog out instead of dissolving part of it.
