Manhole inspection chamber unit problem

[stevek54]

Hello

I have recently noticed a foul smell in the bathroom. The loo flushes the bath and shower drain and there don't appear to be any blockages so I checked the manhole outside the bathroom and some faeces were still in the chamber. When I flushed the loo and watched what happened, water sloshed around in the chamber and most flowed to the main sewer as it should. But some water stayed in the chamber along with the faeces.

The picture below is of the type of chamber we have. The pipe at 6 o'clock is the one through which the loo, shower and bath drain. The one at 3 o'clock channels water from the kitchen (washing machine etc). The other three aren't used and have plastic stoppers on the ends of the pipes. The pipe at 9 o'clock is to the sewer.

When the loo is flsushed water is sloshes around the chamber and some faeces stay in one of the unused channels rather than being directed down the pipe to the sewer. Can this chamber be replaced with one that only has the number of inlet and outlet pipes that we need or is this how they are all designed and is the problem the fitting?

Untitled

• stevek54
• 8 Dec 2012
• 1

 

[noseall]

The foul smell in your bathroom is not due to remnants of waste matter in your inspection chamber.

I know because everyones' system stinks of poo regardless of whether there is solid matter in the manhole or not. Sewer smells 'chimney' through a system and find their way into any unprotected building.

Almost all smells are countered by water filled traps. I should check these first and in particular look at the shower waste if you have one.

 

[noseall]

Also to add:

Do you have an S.V.P or has some clever dick plumber decided to fit AAV's instead?

 

[Hugh Jaleak]

Osma used to offer a blanking cover for unused channels in these chambers, unfortunately detritus build up is fairly common with this type of chamber. Possibly due to having too steep a fall on the incoming pipework, or stack too close to chamber.

Agree with Noseall, either a trap is not sealing, you've a faulty AAV or a broken pipe or joint somewhere thats causing the smell to escape.

 

[stevek54]

Also to add:

Do you have an S.V.P or has some clever dick plumber decided to fit AAV's instead?

Sorry, noseall I don't know what these are. How do I check which I have? It sounds serious.

 

[^woody^]

Smells are stopped from the drains by a water seal in the "u bends" or traps on the pan, basin, bath shower etc

What is common, is for a flush of the toilet (or letting stuff out of a sink or bath) to pull this water out of the bend of an adjacent trap - especially a shower.

So stick your nose by the plug holes of the adjacent appliances and see which one is letting the smell up

Otherwise see where the other end of the vertical soil pipe is - outside or inside and if there is an attachment on the end which may be a valve (AAV) which may be stuck open

 

[Hugh Jaleak]

AAV's are Air Admittance Valves, basically a one way valve that will let air in under negative pressure in the system, but remain shut at all other times to keep smells out. They are fitted on the end of the 4" pipe, usually internally, and if they get stuck open they can allow foul air to escape into the building....

If you trace the stack upwards, see where it goes. If it's internal does it penetrate the roof and vent to atmosphere? (If so the problem lies elsewhere.) If internal it could be boxed in and finish just above the level of the basin, need to check it's not stuck open, (or shut which could cause the traps to be pulled!)

 

[stevek54]

Is this something a plumber can fix or is it a drainage thing that the builder needs to fix?

It doesn't smell constantly just every few months and when I clear the small amount of faeces the smell goes away.

 

[dann09]

Plumbers do groundwork/drainage if req'd.

First, have you checked out the above suggestions? Dont do anything until you know what you are doing and why you are doing it.

Perhaps post a pic looking down the actual in-situ manhole/IC.

Note how the bathroom fixtures waste pipes tie-in to other pipework or to the soil pipe - and, as above, carefully examine all connections esp. the WC spigot connection to the multiquick/CI hub that goes into the wall.

 

[noseall]

Plumbers do groundwork/drainage if req'd.

You have got to be kidding, right?

 

[noseall]

It doesn't smell constantly just every few months and when I clear the small amount of faeces the smell goes away.

I have seen trillions of IC's with shoite in them - plenty of shoite, mine included and there is not the slightest whiff beyond the traps.

Your problems lay elsewhere.

 

[dann09]

If i was kidding i doubt that you would notice it.


The "if required" refers to if it was necessary to dig out the OP's specific IC/drainage.

However, plumbers, in my experience, will do all plumbing groundwork.

We do. We do plumbing amongst other trades, and often set IC's, gullies and house sewers, and trench in water services.

Unfortunately we dont see trillions of IC's, so there you have the advantage of me.

Thanks for taking an interest in my post.

 

[noseall]

A plumber with a shovel in his hand....now that's a novel idea.

Hey Dann chill, i'm only ribbing.

It's only usually us 'grunt' builders who have the brainpower to use a shovel, we leave the finess stuff above ground to those with more delicate hands.

 

[dann09]

Noseall,
Sorry for jumping out like that, i was wrong.
Thing is, i'm so used to the antics of the building trade where you let no man be your master, and so at the first sign of what appears to be a challenge, i dont think, i instantly step up. Not the best way to be, but given the gorps and headbangers i've had to deal with on site ...

 

[Hugh Jaleak]

For reference, the Osma channel covers are part numbers 4D948 (LH) and 4D949 (RH), for use with chamber, part number 4D922 if of any use.