Stand pipes for washing machine and dishwasher

Crowdedhouse_2 · 31 August 2014 at 3:19PM

I have 2 stand pipes inside one of my kitchen cupboards.

One standpipe has the washing machine drain hose poked in to the top of it. The other stand pipe is not in use at all and hasn't been for at least 12 years which was when I moved into the property. I assume the previous owners of this property had a dishwasher or something but don't really know. The unused stand pipe is partly disassembled indoors. The long part of the pipe where the hose goes into is not connected to the p trap. It looks like someone has deliberately separated this part from the p trap. The p trap then goes out thru the wall to the waste pipe outside alongside the p trap for the washing machine.

Over the years I have noticed an intermittent sewer type smell in my kitchen and particularly in the cupboard where the stand pipes and p traps are. I wondered if the unused p trap was responsible and at one stage stuffed a plastic carrier bag into the open top of the p trap in an attempt to stop the smell. This didn't really work so I removed the carrier bag and used some sort of sticky parcel tape and taped up the end of the trap. This has been a bit more successful at keeping the smell at bay but I would like something a bit better than parcel tape. Is there any sort of plastic cap I could buy to put on the end of the p trap or any thing else you could suggest? I don't want to take this pipe out as I don't want the problem of removing it from the outside waste pipe or having to fill a big hole in the wall.

Thanks.

nickcc · 31 August 2014 at 3:39PM

You can buy a cap for the P trap that will be airtight. What happens is the water drys out in the trap and allows the sewerage smells to enter the house. The likes of B&Q or any plumbers merchant will stock the plug.