Soil Downpipe Blocked? Or waste chamber?

[Skyhigh]

Empty the bath, toilet gurgles (air coming back up).
Flush the toilet and the bath 'spits' water (lovely).

Happened one day last month. Flushed the toilet a few times and ran a couple of baths through the system and it seemed fine.

Now its back (past 3 days) and it won't shift.


Checked the soil manhole (big concrete manhole in the back garden) - had about 1 inch of standing waste water in it - couldn't see the channels at the bottom of the hole.
Got the garden hose on it and with the water pressure could just see the 'floor' of the hole.

Left the hose in for a while to see if the water level would rise (as if there was a blockage) - but it didn't - the water stayed about an inch deep.

Ran a few full baths and flushed the toilet a few times to see if I could 'flush' any partial blockages out.

Strangely, also checked the manhole at the same time to see if the water level had risen - as I'd put a load of water down it.....but it was at the same level - still about 1 inch deep - it hand't moved!



Does it sound like the soil down pipe, or the main sewer?

Any help appreciated!




The other two toilets are fine, but I'm pretty sure they go to a different soil chamber (front of the house).
I've also tried (just for a punt) some 'drain cleaner' and also some 'drain unblocker' in the hope they might corrode a potential blockage.

Tried plunging, but hardly anything happens (just get water from the bath/sink overflow).
Nothing 'odd' has gone down the system from us. Its the spare bathroom which we hardly use.

There's no service access on the soil pipe either - as it's an 'inside' soil pipe, all boxed off into the interior wall. :-/

I can see this being expensive to sort

 

[Hugh Jaleak]

Rather concerned you 'cant see the channels' in the manhole. If system is running freely then channel should be clearly visible, and 1" of standing water wont cover it, its a 4" pipe! More likely to be a problem in the drain rather than the stack, but you need to ascertain where it goes.

Be very careful messing about if you've put chemicals down there, likewise if you engage a contractor to clear it, WARN them about use of chemicals. Drain cleaner is a strong chemical and will cause serious injuries if it comes into contact with skin or eyes

 

[HERTS P&D]

Blocked manhole, get it jetted out!!!

Post a pic of your manhole and we can take it from there, probably a blocked interceptor.

Andy

 

[tryitandsee]

as it's an 'inside' soil pipe, all boxed off into the interior walll

The soil pipe may have an AAV that is not opening to allow air into the top of the soil pipe.

www.diydata.com/plumbing/air_admittance_valve/air_admittance_valve.php

www.marleyplumbinganddrainage.com/diyer/content/2/226/air-admittance-valve.htm

 

[dennyboy]

Rather concerned you 'cant see the channels' in the manhole. If system is running freely then channel should be clearly visible, and 1" of standing water wont cover it, its a 4" pipe! More likely to be a problem in the drain rather than the stack, but you need to ascertain where it goes.

Be very careful messing about if you've put chemicals down there, likewise if you engage a contractor to clear it, WARN them about use of chemicals. Drain cleaner is a strong chemical and will cause serious injuries if it comes into contact with skin or eyes

remember going to a blocked sink once - put my hand in to check if there was any blockage in the plug-hole (never ceases to amaze me how many times its that simple) - the silly cow of a tenant didnt tell me she tipped a bottle of caustic soda into the sink - she come very close...

 

[Skyhigh]

Thank you for the reply guys!

I'll get a photo of the bottom of the manhole shortly and put it up.

(I'm a bit of a one for safety, so I'd definitely tell anyone who came out exactly what's been down the drain, etc. Seen too many easily avoidable accidents tbh.)

If I did have to call someone out to flush the drain - and it was a simple job like that - any idea what I'd be looking at? £100? £300? £1,000?

Or would it be worth buying a drain rod kit like this one to give it a try with a plunger?


Cheers,

 

[HERTS P&D]

I would charge you £95 with a 'no fix no fee' policy. You can phone around and ask for a FIXED price. Don't pay a 1/2hour rate, or the bill would shoot up.

But before doing that post a pic and we can advise you from there.

Andy

 

[Skyhigh]

The soil pipe may have an AAV that is not opening to allow air into the top of the soil pipe.

www.diydata.com/plumbing/air_admittance_valve/air_admittance_valve.php

www.marleyplumbinganddrainage.com/diyer/content/2/226/air-admittance-valve.htm[/QUOTE]

I'll nip into the loft tomorrow morning and have a look at the valve to see if its working OK as well.

Its a 4 year old Barratt house, so it wouldn't surprise me if it were that. We've had no end of problems

I'd assume that if it were a blockage (and not the valve) that you could rod the stack from the AAV (obviously, after taking it off..) ?


Cheers guys!

 

[Hugh Jaleak]

A new house of that age I'd be 99% sure they'll have used plastic manhole bases, concrete rings may have been used to build up the chamber on deeper runs. You would be able to see the channels if the chamber was clear (as it should be). It may be the chamber you are describing is a soakaway pit for rainwater.

I'd hazard a guess the problem bathroom links in to the other pipework somewhere under the house. Could be another soil pipe is entering vertically on a 'T', and waste has backed up past the connection. Whilst more frequently used bathroom is ok, it's leaving solid matter in the pipe, upstream of the connection, thus causing problems when you use the (less frequent) bathroom. I suspect CCTV may be the only way to see whats going on

You can try rodding from the loft, but highly doubtful the blockage would be in the vertical section of the stack. You'll need a fair few rods to get to the underground section from up there!

 

[HERTS P&D]

Don't rod from the loft.

Post a picture.

Andy

 

[Skyhigh]

So here's the drain (click for larger images):





The waste water us about 1 inch deep - if I spray the hose in the corner I can see a concrete base.

The brown floating bits....yeah, not soil :-/

(Also crawled up into the loft, right into the corner to see if there was a AAV - couldn't find one, even buried under the insulation)

Cheers!

 

[Hugh Jaleak]

Concrete in the corner is probably the benching. You'll need to poke around with rods, should be able to 'feel' the channel in the bottom. Ascertain which way it flows, otherwise you wont achieve much rodding upstream!

Check neighbours for a downstream manhole, its possible its blocked further along, hence it'll take a fair drop of water to make the level rise noticeably.

 

[Nige F]

The brown floating bits....yeah, not soil :-/

(Also crawled up into the loft, right into the corner to see if there was a AAV - couldn't find one, even buried under the insulation)

Cheers!

The AAV will be in the boxing in the bathroom then , not needed to be taken into roofspace - that`s optional .

 

[tryitandsee]

Unless you can see the soil and vent pipe coming through the roof/outside, which would mean you don't have an AAV.

 

[Skyhigh]

The brown floating bits....yeah, not soil :-/

(Also crawled up into the loft, right into the corner to see if there was a AAV - couldn't find one, even buried under the insulation)

Cheers!

The AAV will be in the boxing in the bathroom then , not needed to be taken into roofspace - that`s optional .

It doesn't enter the loft cavity - so it looks like it terminates in the boxing (that is, if there is an AAV..).

Time to crack out the rods and give the drain a bit of a run through.


Cheers