Why does the drain hole in the washbasin in the bathroom always have a strong rancid smell?

In addition, whether the gap between the lower drain pipe and the casing of your home is tightly blocked, and the building where you live, in addition to the poor ventilation measures, there is also if your home is not on the top floor, then the drainage of the upstairs neighbors is also through the sewer pipe of your house, so there is a pungent odor.

In addition to ventilation measures, it is recommended that you consider changing the sewer to a separate sewer, so that you can do it.

It should be that you didn't get a good ventilation channel when you laid the sewer pipe, the water level outside is higher than your house, and the smell poured in, and you have to find someone to get it again.

In addition to the poor ventilation measures, there is also the fact that if your house does not live on the top floor, then the drainage of the upstairs neighbors is also through the sewer pipe of your house, so there is a pungent odor.

In addition to ventilation measures, it is recommended that you consider changing the sewer to a separate sewer, so that you can do it.

That's right, the pipe of your washbasin is connected to the toilet drain pipe under the floor slab, so that there will be no smell under the actual circumstances, but the situation you said must be that the drainage ditch downstairs is not sealed enough, so that there is air flow, causing the smell to pour up, find the property to check the gutter. Ask if this happens upstairs and downstairs as well.

Maybe your home doesn't have a trap in the lower drain.

When building a house, we didn't do a good job of separating wastewater.

So is my family. Alas. My solution is:

Light some sandalwood in it, or burn a candle, burn the XXXX (hehe, I don't know what it is) gas in the air and you'll be fine.