How to unblock a bath — including baths with no plughole access
Baths block differently to showers because of the overflow. Here's the method that actually clears them.
Why baths are harder than sinks
A bath waste has two openings into the same trap — the plughole and the overflow — joined by a flexible pipe behind the bath panel. Any plunging you do at the plughole vents straight out of the overflow unless you block it first. That single fact is why most people decide a bath 'can't be plunged'.
Bath traps are also usually shallow and hidden behind a sealed panel or a tiled bath surround, so the strip-and-clean approach that works under a sink often isn't available.
Step 1 — get the hair out first
Unscrew or lever out the plughole grille. On a pop-up waste, turn the plug anticlockwise while holding the linkage, or unscrew the centre screw.
Feed a Zip-It strip or flexible drain brush in and pull. Baths hold a surprising amount of hair bound with body oil and conditioner. Get every pass out until the tool comes back clean.
Step 2 — block the overflow, then plunge
Stuff a wet cloth firmly into the overflow plate under the taps and hold it there, or get someone to press a hand over it. Fill the bath with two or three inches of water so the plunger cup is submerged.
Plunge with sharp, short strokes, keeping the cup sealed against the base of the bath. Twenty strokes, then release and watch. If the water level drops suddenly, you've moved it.
Step 3 — soda crystals and hot water
Once flow has partly returned, tip a large mug of soda crystals down the plughole and follow with hot water from the kettle, cooled for a minute. This clears the greasy film that traps the next round of hair.
Do this monthly and you'll rarely block a bath again. It's the cheapest maintenance in the house.
Step 4 — reach the trap if you can
If there's a removable bath panel, take it off. You'll see a shallow trap and the flexible overflow pipe. Put a shallow tray underneath, unscrew the trap by hand, empty it and refit finger-tight plus a quarter turn.
If the bath is boxed in and tiled, don't start cutting tiles. A drainage engineer can clear it from the waste run with a mini-jetter without opening anything up.
Step 5 — decide whether it's the bath or the drain
Run the basin and flush the toilet. If those are fine and only the bath is slow, it's local — keep working the waste. If everything upstairs drains slowly or the downstairs toilet gurgles, the stack or the underground drain is blocked.
Look at the outside gully or manhole while someone runs the bath. Water rising outside means the problem is underground and DIY tools won't reach it.
Whose drain is it?
If the blockage is in the underground run, the next question is who pays. Most shared drains and everything past your boundary transferred to the water company in 2011, and they clear those free of charge. Our free drain responsibility checker gives you an answer in about thirty seconds.
If it turns out to be theirs, we'll tell you to call them rather than take your money.
Getting us out
DrainFixer covers East Grinstead and a 20-mile radius, 24 hours a day, as a small family-run firm. Call 0330 1331 347 for a clear price before any work starts.
Frequently asked questions
Why won't my plunger work on the bath?
Because the pressure escapes through the overflow. Block the overflow plate under the taps with a wet cloth and hold it firmly while you plunge — most baths clear immediately once you do.
How do I unblock a bath with no access panel?
Work through the plughole: hair tool first, then blocked-overflow plunging, then soda crystals and hot water. If that fails, an engineer can clear the waste run with a mini-jetter without removing tiles or panels.
What causes a bath to block?
Hair bound together with body oil, soap scum and conditioner, forming a plug in or just past the trap. Hard water areas around East Grinstead also see scale build-up narrowing the waste over time.
Is a slow bath a sign of a bigger drainage problem?
It can be. If the basin, toilet or downstairs fixtures are also slow, or you hear gurgling, the underground drain is likely restricted and needs jetting or a CCTV survey.