Is this safe or can gas back-up?

[Julsie]

Hi,
A while ago , we has an odd-job guy fit a new downstairs loo. He's attached the washing machine and basin waste to the top of the toilet waste, see photo. We have a septic tank and sewage smell coming up when we flush. I've assumed this is because the seal where the waste enters the ground needs redoing, but is it because he's put the waste pipe where it is? There seems to be no way of stopping the gases coming back? The pipe goes to the washing machine first, then basin,
Thanks

 

[Last Plumber]

Is there a trap on the washing machine waste and basin waste?

 

[Julsie]

Is there a trap on the washing machine waste and basin waste?

There's a bottle trap under the basin but nothing behind the washing machine

 

[Last Plumber]

There's a bottle trap under the basin but nothing behind the washing machine

There needs to be a deep seal trap to cover both. The soil pipe at the rear of the WC will be connected directly to the tank. If there is no seal, you will get gases/odours in the house.
Does the basin trap siphon out when the WC is flushed or the washing machine empties?

 

[Deleted member 120897]

Looks like imo, the pan connector isn’t sealed.

 

[Julsie]

There needs to be a deep seal trap to cover both. The soil pipe at the rear of the WC will be connected directly to the tank. If there is no seal, you will get gases/odours in the house.
Does the basin trap siphon out when the WC is flushed or the washing machine empties?

I don't know how I'd be able to tell if the basin trap is siphoning out?

 

[Deleted member 120897]

I don't know how I'd be able to tell if the basin trap is siphoning out?

Does a smell emanate from the basin at all?

 

[Julsie]

Does a smell emanate from the basin at all?

I think it might have today, which is why I posted. But it's hard to tell as the smell gets so bad in there at times. It's a tiny room.

 

[Chuck]

I think it might have today, which is why I posted. But it's hard to tell as the smell gets so bad in there at times. It's a tiny room.

You should really get a qualified plumber to take a look and sort the problems out for you. Sewer gas, which is what you can smell, is not good for you and at high levels is downright dangerous.

 

[Ric2013]

Well if the washing machine standpipe is not trapped, that is the likely problem, or a joint isn't sealed properly somewhere.

 

[Julsie]

Well if the washing machine standpipe is not trapped, that is the likely problem, or a joint isn't sealed properly somewhere.

Thanks for the replies