Bathroom Sink Won't Drain

[yeeew87]

We have only been living in this house a few months but have began to notice our bathroom sink won't drain (water sits in the sink and drains very very slowly).

I have taken the trap off, it wasn't blocked but gave it a clean anyway. Still the same issue, all other drains in the house seem to drain easily. photos attached - any ideas?

Thanks.

 

[Reach4]

After the sink sits unused at least overnight, how much water can you pour into the bowl before the water starts backing up? That amount can be used to compute an estimate of how far down the pipe the blockage is.

You appear to have an S-trap, but that won't affect this slow-drain symptom.

 

[Sponsor]

 

[yeeew87]

After the sink sits unused at least overnight, how much water can you pour into the bowl before the water starts backing up? That amount can be used to compute an estimate of how far down the pipe the blockage is.

You appear to have an S-trap, but that won't affect this slow-drain symptom.

The water sits in the S-Trap as usual overnight, so when I begin to fill the sink it's almost as if no water flows past the trap and just begins to build up in the sink within a few seconds. Not sure if there may be an issue with the vent?

 

[Reach4]

The lack of a regular or AAV vent won't cause that symptom.

Let the bowl fill to the overflow, and see if the water goes down the overflow. Besides the water rising event to the top of the overflow (when you would turn off the faucet) as you would expect with an actual clog, I could see two other possible behaviors.

1. The water will not rise as high as the overflow with the stopper open. The water suddenly flows out of the drain normally first. This would indicate one kind of thing.
2. Water rises to the overflow, but the overflow takes plenty of water.

 

[yeeew87]

The sink would of overflown if I didn’t turn it off.

 

[Reach4]

There went my non-clog theories.

You need to snake your drain path, unless you can get a drain bladder to pressurize the drain lines and blow the clog through.

 

[Terry]

Often I find in the the tailpiece of the drain leading to the p-trap.
Sometimes I push a stick with a wad of paper through that to clear it with a bowl below to catch the hair and goo. I remove the trap first.

 

[yeeew87]

UPDATE.

I have taken off the S-Trap again and poured some sodium hydroxide crystals directly into the base pipe followed by a cup of water, left for 20 minutes and this seems to of fixed the problem for now... Previously I poured the crystals directly into the drain but i suspect due to the blockage they weren't really flowing out of the S-bend and reaching the problem area.