Putrid smell coming through dishwasher/sink - trap needed

Hi all,

I'll apologise for my ignorance in advance here.

I've moved into a flat and there is an awful smell which sometimes comes through the dishwasher and also occasionally the sink. It doesn't seem to correlate time wise with any particular activities i.e. it doesn't appear just after the dishwasher is used, or just before, or with any sort of regularity. It just comes and goes randomly. I've also tried cleansing the dishwasher with one of those cleaning fluid bottles you leave for a cycle (several times) and I've used cleaner down this sink to clear any accumulated food waste which might have gotten stuck.

From what I read online the smell does seem to match people's description of sewer gases. I have attached a photo of how the setup looks behind the dishwasher. The waste pipe from the dishwasher in coming in from the foreground and going into a standpipe (there is duct around the top to hold it there it seems). The pipe from the right is coming from the sink and then the dark grey pipe goes through the wall towards the bathroom. From what I've read online I would have thought that there needs to be a trap at the bottom of the standpipe and that will stop the smell from coming back, but I have no idea how to deal with the connection with the grey pipe, which seems to be stuck fast and heads on through the wall.

Is a trap even a solution here? Any help is greatly appreciated as the smell is becoming unbearable and from what I've heard may even be harmful to your health.

Regards
Neil

Install a HepVo waste valve with a compression adapter and a washing machine spigot onto the top of the pipe you've taken a photo of. That'll cure it

Thanks for your help Muggles. I'll have a look into this.

You say the smell also comes from the sink?

Is there a trap there?

I got so impatient I ended up getting a plumber in the next day to install a conventional trap. Thanks for your comments guys.