sewer smells in ensuite bathroom

[Colin Green]

We occasionally get sewer smells in our little used ensuite room in our new loft conversion. I suspect it happens when the u bend under the basin dries out as it is plumbed almost straight into the top of the soil stack.

We last noticed it on Christmas day when we were getting the loft bedroom ready for friends staying over on Boxing Day evening. I ran a load of water down the sink and the smell hasn't come back.

What is a good way of putting a permenant stop to this? The sink drain is all in 40mm plastic pipe. There's 1 90° elbow coming out of the trap, a drop of 10 - 15cm, another elbow and mabye 20cm of horizontal pipe that tees into the stack. I'm happy to replace all this with something that will stay closed when the water dries up. What could I fit?

 

[Dan Robinson]

Change trap to a HEPvO.

Or get in the habit of running a bit of water down it each week.

 

[Colin Green]

Thanks, I'll pick one up the next time screwfix is open.