Smelly drain doing my head in

[SimonD]

My kitchen waste is causing me a headache - it's smelly and getting worse, even though I've tried to fix it.

 

Originally it wasn't smelly and all was good. It began smelling only when the dishwasher was started and did it's first flush. Just in case I installed an anti-siphon trap at the sink. Not change. I then went to the soil stack boss and double checked it's all sealed up and layered on some extra solvent weld and did some general checking of joints, which all seemed good. I thought I might have resolves it, but no, the smell is worse than ever. 

 

It's an internally routed soil stack with an aav at the top just below the very high ceilings. The waste pipe boss is a normal strap boss with rubber (could the problem be here despite double checking?). The soil pipe does a wiggle through steels - this is my only know sin with this installation as I used a flexible connector to meet the soil pipe below the floor, which goes into a push-fit soil pipe. The smell is no noticeable in the ensuite below where the soil pipe is exposed so I can try to work this out.

 

My suspicion is it's either something to do with the strap boss even though it seems to be properly welded in there, or maybe the aav at the top of the soil stack? I don't think it's the flexible connector unless it's split where it doesn't allow fluid leak. 

 

Help....

[Nickfromwales]

3 minutes ago, SimonD said:

My kitchen waste is causing me a headache - it's smelly and getting worse, even though I've tried to fix it.

 

Originally it wasn't smelly and all was good. It began smelling only when the dishwasher was started and did it's first flush. Just in case I installed an anti-siphon trap at the sink. Not change. I then went to the soil stack boss and double checked it's all sealed up and layered on some extra solvent weld and did some general checking of joints, which all seemed good. I thought I might have resolves it, but no, the smell is worse than ever. 

 

It's an internally routed soil stack with an aav at the top just below the very high ceilings. The waste pipe boss is a normal strap boss with rubber (could the problem be here despite double checking?). The soil pipe does a wiggle through steels - this is my only know sin with this installation as I used a flexible connector to meet the soil pipe below the floor, which goes into a push-fit soil pipe. The smell is no noticeable in the ensuite below where the soil pipe is exposed so I can try to work this out.

 

My suspicion is it's either something to do with the strap boss even though it seems to be properly welded in there, or maybe the aav at the top of the soil stack? I don't think it's the flexible connector unless it's split where it doesn't allow fluid leak. 

 

Help....

Stench of sewerage? Is it coming back through the dishwasher?

[Beelbeebub]

AAV could have failed - in which case the smell should be worse there. 

 

The other thing we had with a waste disposal unit was the flow rate was too high for the (old and clogged) pipework so we ended up displacing air back up via the overflow, which was pretty stinky. 

[FarmerN]

Our dish washer is connected above the U bend below the sink and can smell.

 

Every 3 months I have to unscrew dishwasher waste connection, clean and reconnect. Problem solved for me.

Running a cleaning cycle in the dishwasher doesn’t sort it. It’s just a badly designed waste connection, that allows a build up of crud.

The washing machine  connection in the utility is identical and also requires the occasional clean but not as often.

[Bramco]

I've noticed that if the overflow connection is a corrugated pipe and it attaches almost horizontally into the plughole base, then you can get backflow from the sink into the overflow pipe connection with associated detritus which eventually starts to stink.  The only way to fix it is to get under the sink, disconnect the overflow pipe and clean it out.

 

A bucket underneath is a good idea as well as a mask.

[SimonD]

4 hours ago, Nickfromwales said:

Stench of sewerage? Is it coming back through the dishwasher?

 

Good question. It's not actually the same as you get when you have an open end to a soil pipe, it's a slug of smell that actually slightly in taste.

[SimonD]

4 hours ago, FarmerN said:

Our dish washer is connected above the U bend below the sink and can smell.

 

Every 3 months I have to unscrew dishwasher waste connection, clean and reconnect. Problem solved for me.

Running a cleaning cycle in the dishwasher doesn’t sort it. It’s just a badly designed waste connection, that allows a build up of crud.

The washing machine  connection in the utility is identical and also requires the occasional clean but not as often.

 

4 hours ago, Bramco said:

I've noticed that if the overflow connection is a corrugated pipe and it attaches almost horizontally into the plughole base, then you can get backflow from the sink into the overflow pipe connection with associated detritus which eventually starts to stink.  The only way to fix it is to get under the sink, disconnect the overflow pipe and clean it out.

 

A bucket underneath is a good idea as well as a mask.

 

4 hours ago, Beelbeebub said:

he other thing we had with a waste disposal unit was the flow rate was too high for the (old and clogged) pipework so we ended up displacing air back up via the overflow, which was pretty stinky. 

 

All good pointers, thanks.

 

I will dutifully strip it all down and clean with associated PPE! 

[Nickfromwales]

38 minutes ago, SimonD said:

 

Good question. It's not actually the same as you get when you have an open end to a soil pipe, it's a slug of smell that actually slightly in taste.

Sounds like grey water stink vs SVP “stench”. 
 

FWIW, the only smell that makes me being my lunch immediately back up, is when cutting ancient, blocked kitchen sink waste pipes out; the black sludge is just horrific, compared to a whiff of 💩.

 

Do you have a pic of the plumbing? 

[SimonD]

4 minutes ago, Nickfromwales said:

Do you have a pic of the plumbing? 

 

Oh dear, I'm under scrutiny 😁 I'll have to remove drawers and stuff, but yes I totally agree on that blocked kitchen sink stuff - I had to blow out a blocked condensate drain once and that was enough for me to stipulate that'll I'll never do general plumbing! I lost a customer over this too. I visited to fix the boiler and the customer had cleared out the cupboard under the sink and said, while you're here can you... I gave him my minimum price and told him it was this price because I just don't do this work 😏

[Nickfromwales]

9 minutes ago, SimonD said:

 

Oh dear, I'm under scrutiny 😁 I'll have to remove drawers and stuff, but yes I totally agree on that blocked kitchen sink stuff - I had to blow out a blocked condensate drain once and that was enough for me to stipulate that'll I'll never do general plumbing! I lost a customer over this too. I visited to fix the boiler and the customer had cleared out the cupboard under the sink and said, while you're here can you... I gave him my minimum price and told him it was this price because I just don't do this work 😏

You princess lol 🤣

 

9 minutes ago, SimonD said:

Oh dear, I'm under scrutiny 😁

Show us your ti….. pipes.