Smell from Ensuite only in the evening

[kevin123]

Hi all, here’s hoping you can help with a bizarre issue were experiencing.

For a few months now late in the evening (after 8pm) we have this awful, eggy, sewage smell coming in to our bedroom from (we guess) the en-suite.

Sometimes it appears by itself but when it’s at it worse we’ve worked out it comes when we either run the tap in the sink or flush the toilet.

As a test we decided to stop using the en-suite at bedtime and used the main bath room instead, when we did, most of the time there was no smell in our bedroom. If there was a smell it was only faint.

The weird thing is I can smell it more in the bedroom just the other side of the en-suite rather than the en-suite itself.

I’m ruling out dead animals due to the fact it only happens at night.

Also, I’m not sure it’s being caused by standing water as the smell isn’t there in the morning after we flush the toilet, take a shower and it doesn’t appear when I get home from work and use that toilet. It’s just in the evening.

We have tried cleaning out the gunk from the plug holes, dumping bleach and drain unblockers down plugs with limited results.

In the past we did sometimes get the smell in the kitchen but we haven’t smelt it in there for months now and when we did it was on the odd occasion.

Really confused as to what it could be, does anyone have any ideas or suggestions?

If we were to get the plumbers out would they have to come out at night when it smells? Could they check anything during the day?

What kind of checks / tests would you expect them to do and any rough estimate on price?

 

[HERTS P&D]

Try pouring some bleach into the basin/bath overflows.

Andy

 

[Nige F]

Have you got a proper open vented soil pipe in the house ?

 

[kevin123]

Hi both - thanks for your replies

@ Andy - must admit i missed off the overflow for the sink when cleaning with the bleach so i've pored some down and we'll see if that helps.

@ Nige - i'm pretty much a dummy when it comes to plumbing but i'm reading up and learning as i go along so forgive me if i ask what may seem a stupid question. How would i check if i have an open vented soil pipe?

I assume this is the vent pipe that should go out through the roof? To check if it's open, would it be a case of busting out the ladder and checking the vents on the roof aren't blocked?

I've read about AAV's but how would i tell if i've got one and if it's faulty?

 

[Hugh Jaleak]

Eggy smell is often a sign of Hydrogen Sulphide (H2S), nasty stuff, and found in sewers. Evening time then more water is used, and therefore more activity in the drains which could result in air being displaced, and causing problem you describe. Look outside on the roof, do you see a 4" diameter pipe sticking out, with a cage on the top?

Also, check the 4" soil pipe from the en suite toilet. Is this boxed in within the bathroom, or does it appear to continue upwards into the loftspace? If it stops at a low level within the room then usually means an AAV is fitted. I would hazard a guess from what you've said so far, the en suite has an AAV on the top of the soil pipe, and this is sticking open, allowing the odour into the room.

 

[kevin123]

Hi - thanks for the reply.

I cant see where the soil pipe from the en suite toilet goes as it's all boxed in.

I've look all over the roof and there's no pipe sticking out, I assumed it was therefore ending in the loft so i had a look up there. I've found a pipe terminating in the loft pretty much above the area of our bedroom where the smell is first smelt so i'm assuming this is the soil pipe. It's pretty had to get to as i don't have loft boards down in that section but i managed to grab a few pics (hope i've attached them correctly!), does that look like a soil pipe?

If so, should there be anything on top of it?











When i was in the loft and my wife ran the tab in the en suite i could hear the water running in the pipe no problem so it's definitely connected to the en suite in some way.

 

[Belboz]

If that is the top of the en suite soil pipe then I am 100% sure it should not be open like that. Shouldn't it have some sort of vent??

 

[Terry lambert]

Yep, certainly looks like it

 

[Bosswhite]

Fit an Air Admittance Valve, simple, just push it into the top of the pipe,
Maybe whoever put the lagging in the roof space may have taken the original off and forgot to replace it.
That smell you are talking about is Sewer Gas which is highly flammable.
http://www.diydata.com/plumbing/air_admittance_valve/air_admittance_valve.php

 

[Hugh Jaleak]

I'm a bit concerned as to why that has been left open like that, I'm wondering if it's a classic builders cock up, and that pipe was always intended to be continued through the roof. The en suite sounds like it is terminated with an AAV inside the boxing, which isn't a problem usually. I'd be a bit concerned about fitting an AAV to that open end at present, until it's established what ventilation is provided, (if any), elsewhere on the system.

How old is the property?

 

[Bosswhite]

There appears that there is still the smell of sewer gas within the property which could be potentially dangerous, it wants sorting out ASAP

 

[kevin123]

hmmm ok, how do i tell if it needs an AAV or not?

The property is about 14 years old but we only moved in 9 moths ago.

Theres no smell at the minute because we're not using the en suite at night. How come using the other bathrooms / toilets doesn't result in the same smell or would they vent through a different pipe?

 

[endecotp]

Just a thought - could that be a bathroom fan extractor? Unlikely I think but worth checking.

 

[Hugh Jaleak]

Basically a soil pipe should either be taken to an open end to vent externally or be fitted with an AAV to terminate internally. Rules usually dictate the highest point of the drain should be open to atmosphere, to allow any gases or odours to safely and unobtrusively escape from the system.Other connections lower down can be terminated with an AAV,

Without seeing the layout of the property and drainage system its difficult to tell, but chances are the other bathrooms may use independant stacks and enter the drainage system further down. Using the ensuite would displace air in the drainage system, and possible give rise to the problems you are experiencing. I would get a plumber to look over the property, and if there is not currently another open vent, I'd bite the bullet and get that open end in the loft extended to penetrate the roof and vent externally.

 

[kevin123]

There is an extractor fan in the en suite and i'm also struggling to see where that is venting. I've noticed that my neighbours that have an identical styled house have a vent on their roof above their en suite that we dont. It's not a pipe sticking out though so i dont believe it's the soil pipe, it's more of a normal roof tile with a slight raise in it at the front.

What would the affect on the system be if i put an AAV on that open pipe in the loft? Would it cause serious issues if it turns out it shouldn't have one on?