How to Clear a Toilet Choke in an HDB Flat (and When to Stop)

Use a flange plunger, keep water over the cup, and pump firmly while holding the seal.

A flange plunger, sometimes sold as a toilet plunger, has a soft sleeve under the cup that fits into the bowl's outlet. A flat cup plunger, made for sinks and floor traps, leaks air in a toilet. HDB says to place the plunger over the waste hole and pump vigorously; the blockage usually clears after a few pumps.

1. Make sure water covers the plunger cup; add a bucket of water if the bowl is low.
2. Fit the flange into the outlet at an angle so no air is trapped.
3. Push down slowly the first time to squeeze the air out.
4. Pump 15 to 20 firm strokes, keeping the seal on each one.
5. Pull the plunger off sharply on the last stroke.
6. Repeat for two or three rounds.
7. Test with a bucket of water, not a flush, before you trust it.

Once a bucket goes straight down, flush once and watch the floor trap.

Try a toilet choke pump next, then a closet auger. Both work on chokes in the bowl or just past it.

Toilet choke pump

A toilet choke pump is a cylinder or bellows plunger that pushes and pulls much harder than a rubber cup. Use it the same way: water over the outlet, a tight seal, strong strokes. Expect more splashing.

Closet auger

A closet auger has a short cable inside a rigid tube with a rubber-sleeved bend, so the metal is kept off the porcelain. Rest the bend in the outlet, crank the handle as you feed the cable in, then pull it back to hook out the blockage. Don't force it; if it jams hard, you may be pushing an object deeper. A long drain snake or a bent wire hanger scratches the glaze.

No plunger? Try dish soap and hot water

If the bowl isn't full, squeeze in plenty of dish soap, then pour in a bucket of hot tap water steadily. Wait 15 to 30 minutes. This only helps with tissue and soft waste. Use hot, never boiling, water: a sudden temperature change can crack a ceramic bowl.

What not to use:

• Caustic soda, choke acid or other drain chemicals: they rarely shift a solid choke and splash back when you plunge.
• Two products mixed together, which can give off harmful fumes.
• Air-blast drain guns, which can blow dirty water back out.

Watch the floor trap and the other drains. If they back up too, the blockage is in the pipe, not the bowl.

• The auger goes all the way through, but the bowl still drains slowly: the choke is further along the pipe.
• The floor trap gurgles or rises when you flush: the choke is past the point where the toilet and floor trap pipes join, in the branch pipe or further down.
• The floor trap rises when nobody in your flat is using water: suspect the main stack.
• Neighbours on the same stack have the same problem: report it to your town council.

A choke past the bowl needs a powered auger; plunging harder won't reach it. Under HDB's pipes care guide, branch pipes are the owner's and main sanitary pipes are the town council's. For a floor trap problem on its own, see the guide to a choked or smelly HDB floor trap, and for disputes, who pays for a choke in your pipe or the common stack.

Most repeat chokes come from what goes into the bowl, not from the toilet itself.

• Too much toilet paper in one flush.
• Wet wipes, including ones labelled "flushable".
• Sanitary pads and diapers.
• Cotton buds, dental floss, cat litter and children's toys.
• Cement or tile debris washed down during renovation.

HDB's toilets guide warns against disposing of sanitary pads or diapers in the water closet. Newer cisterns also use less water: under PUB's water efficiency labelling guidebook, a 3-tick dual-flush cistern uses 3.5 litres or less for a full flush. Less water carries a bulky load a shorter distance, so use the full flush for paper and flush in stages.

A bowl that chokes every few weeks with normal use may have something stuck in the trapway, or set cement: a plumber's job.

Stop after two or three rounds of plunging and one auger attempt, or straight away if something solid went down.

Also call one if the floor trap backs up, the same toilet chokes again within weeks, or the bowl is cracked or rocks. PUB lets a handyman clear a toilet blockage without a licence, but HDB requires a PUB Licensed Plumber to install, replace or remove a toilet bowl, including taking it off to reach a blockage. If a job means taking the bowl off, ask who will do it.

The price rises when the choke is past the bowl, needs a powered auger, keeps coming back or means taking the bowl off. Each job is priced separately. For an accurate price, send a photo of the water level in the bowl, a photo of the bathroom floor trap, and a note of anything that went down the toilet. A damaged bowl is a toilet repair job. See also choke clearing cost in Singapore and the full plumber price list for Singapore.