Smelly Washing Waste Trap when Toilet Flushed

[NigelJH]

Good morning

I have a washing machine now installed in the cellar and the waste pipe is connected to a pipe that is connected to the main waste pipe that goes down to the sewer but now when the toilet upstairs is flushed a rotten egg smell is coming for the washing machine trap . I have checked the trap and its clean inside and the washing washing it self is not smelling its seems to be coming from the main waste pipe, How can I stop the smell do I have the wrong trap installed?

(see attached picture of pipe going into trap)

 

[exedon2]

Totally wrong trap! At very least needs upstand trap though in that position in a cellar i would used a hepv0 trap fitted vertically with an extension on top

 

[NigelJH]

I have a p trap will that work for now

 

[NigelJH]

The p trap I have is the wrong size its to small, Should the fitted bottle trap have some water in it to stop any smells coming back or would a p trap be ok in its place

 

[exedon2]

If there is no water in trap that's the problem.
It really wants replacing ! I suggested the hepvo trap as it would not only cure problem but would also not leak water or worse all over if drains blocked.
Look on screwfix site they do hepv0 also mcalpine equivalent you need 40mm one also 1 1/2 x 40mm strait adaptor mcalpine do that as well
Take existing trap off replace with elbow short bit of pipe then trap with adaptor screwed on say a 250mm length of in that away you go.
Be a good idea to clip all waste pipe up properly as well.