A toilet that clogs every week is a pattern, and the plunger isn't the fix. Repeat clogs come from four places: a flush that's too weak, something stuck in the trap inside the toilet, a blocked vent, or a partial blockage in the line past the toilet. Here's how to tell which one you have.
First: is it only the toilet?
Flush and watch the other drains. If the tub or shower bubbles, gurgles or fills with water when the toilet flushes, or several drains are slow at once, the problem is past the toilet, in a shared branch or the main sewer line. Stop using water and see what to do when the main line backs up. If only the toilet is slow and everything else drains fine, the problem is in the toilet, its trap or its own short drain line. For a one-time clog, start with how to unclog a toilet. This post is about the clog that keeps coming back.
1. Low-flow bowls and a weak flush
Federal rules have limited new toilets to 1.6 gallons per flush, and EPA notes that older toilets can use as much as 6 gallons (EPA WaterSense). In California, toilets sold since January 1, 2014 can use no more than 1.28 gallons per flush under Assembly Bill 715 (California Energy Commission report). Many first-generation 1.6-gallon bowls from the 1990s simply didn't flush well. Newer high-efficiency toilets are designed to clear the bowl on less water, and WaterSense labeled models are tested for flush performance.
Before blaming the toilet, check what you can see:
- Tank water level. It should sit about an inch below the top of the overflow tube. Too low means a weak flush.
- Flapper and chain. A chain with too much slack lets the flapper close early and cuts the flush short. A worn flapper also wastes water; see how to fix a running toilet.
- Rim jets. Mineral scale can clog the small holes under the rim and the siphon jet at the bottom of the bowl, which slows the flush.
- How much paper. Thick, quilted paper in big wads is a common cause on low-flow toilets. Flush twice, partway through, if you need to.
2. Something stuck in the trap
Every toilet has a curved trap built into the porcelain. When something that doesn't dissolve gets lodged in it, such as a wipe, a cotton swab, dental floss, a feminine product, a toothbrush or a child's toy, the plunger pushes water past it and the toilet works again for a while. Then paper catches on the object and the clog comes back. Our what not to flush list covers the usual suspects.
A toilet auger (also called a closet auger) is made for this. Its rubber-sleeved bend protects the porcelain and its short cable reaches through the trap. If the auger can't grab the object, the toilet has to come off the floor so the trap can be cleared from below, and the wax ring gets replaced when it goes back down. See how to use a drain snake for the basics, but skip a regular sink snake in a toilet; it can scratch the bowl.
3. A blocked vent
Every drain needs a vent pipe through the roof so air can follow the water down. When leaves, a bird's nest or debris block the vent, the toilet flushes weakly and leaves waste and paper behind in the trap. Watch for gurgling, bubbles rising in the bowl after another fixture drains, and a bowl water level that drops or rises on its own. Our gurgling drains guide explains how to tell a vent problem from a clog. Please don't climb onto the roof to check it yourself. A plumber can test the vent and clear it safely.
4. The branch line or the main line
If the toilet clogs and other drains act up too, the blockage is farther along. In older Burbank, Glendale and Valley homes, the usual causes are tree roots in the sewer line, a sagging section of pipe (a belly) that holds waste, wipes that snag on rough cast iron or clay joints, and grease from the kitchen meeting toilet paper downstream. Our post on why a main line keeps backing up goes deeper, and why a drain keeps clogging covers the patterns.
The fix is a proper drain cleaning through the cleanout, and if the line keeps clogging, a sewer camera inspection (free estimates at Rooter Pros) to see roots, cracks or a belly instead of guessing.
What it costs to clear a toilet in LA
These are published ranges from LA-area plumbers and cost guides. They're a sanity check, not a quote.
| Job | Published LA-area range | Source |
|---|---|---|
| Toilet drain cleaning | $150–$350 | Angi (Los Angeles) |
| Toilet auger | $100–$250 | A+ Electric & Plumbing (LA) |
| Single fixture (sink, tub, shower or toilet), Glendale & Burbank | $150–$350 | Alpha-Beta Plumbing (cost guide) |
| Single fixture clearing, LA & SFV | $145–$295 | Last Drop Plumbing (Reseda) |
At Rooter Pros, sink, tub and toilet drains get a free estimate: call (818) 669-9019 and you get the price before any work begins. New customers can also ask about our $49 first-time drain cleaning coupon: new customers only, one per household, one drain or line per visit, residential only, Monday–Friday 7am–5pm, accessible ground-level cleanout required, not valid with other offers. It's a new-customer special, not our regular rate. If an old toilet is the real problem and you'd rather replace it, toilet installs are simple: call us for a free estimate. See our pricing page and the drain cleaning cost guide for more.
How to keep it from coming back
- Flush only toilet paper and waste. Put a small trash can in the bathroom for wipes, swabs, floss and feminine products.
- Use less paper per flush, or flush partway through, especially on an older low-flow toilet.
- Keep the tank set right. Check the water level and the flapper chain once in a while.
- Keep the lid down if small kids are around. Toys in the trap are one of the most common repeat clogs we see.
- Skip chemical drain openers. They rarely reach a clog in the trap, and they can crack porcelain with heat.
- Note the dates. If the toilet clogs on a schedule no matter what you do, the line needs cleaning or a look with a camera.
When to call
Call a plumber if the tub or shower fills when the toilet flushes, more than one drain is slow, the toilet clogs again within days of plunging, water leaks around the base, you smell sewage, or the plunger and a toilet auger don't clear it. If you've used a chemical opener, say so before anyone works on the toilet.
Toilet clogging again in Burbank, Glendale or the Valley? Rooter Pros clears the toilet, its trap and the line beyond it, and tells you what's causing the repeat clogs. Licensed & bonded (CSLB #917630), open 24/7, with free estimates, flat-rate pricing and no overtime charges.
Call (818) 669-9019Prices in the table are typical published ranges from other Los Angeles-area plumbers and cost guides as of October 2026. They are not Rooter Pros quotes and change over time. Your price depends on your home. Sources are linked in the table. Flush volume figures are from EPA WaterSense and a California Energy Commission report on AB 715.