Intermitent Rotten cabbage Smell

[Aston1]

Hi, apologies if this is in the wrong forum but thought it would be closest?
I have a rotten cabbage smell in only one upstairs bedroom which can be quite pungent some days and then completely gone on other days? No other room in the house has this smell. Now, before you ask, the house is very clean which makes it all the worse. I wondered about sewer gas but all traps are used regularly and so shouldn't be dry. The house is 30 years old and is situated at sea level. No other room is affected and the house attached to us (semi) does not smell it although their bedroom is the other side of the wall. Our bathroom is next to the bedroom and the stackpipe runs up the wall between the bedroom and bathroom. We leave a small window open in the bedroom everyday but the smell is either there or not regardless. I even think I smelt it coming on worse during the night once whilst I was lying awake? We have no pets. The central heating is an open vented system with tank in the loft and hot water cylinder in the landing cupboard.
Anyone have any ideas?
Many thanks. Mark

 

[slapper]

Check your soil pipe for a fitting called an Air Admittance Valve, AAV

Maybe some one can post a picture of one ?

These sometimes stick open and allow sewer gases int0 the property

It will be on 2nd floor more than likely

 

[ree]

Why not post a pic of the outside wall with the soil stack?

Is your kitchen below the bedroom?

 

[Aston1]

Thank you for the responses so far.

I will look into whether we have an AAV fitted and assess its condition. This will probably have to be the weekend now?

The soil stack is located between two internal walls and exits through the roof. The kitchen is at the opposite end of the house on the ground floor.

Thank you.

 

[ree]

If you are venting thro the roof then its unlikely that an AAV is fitted unless the vent terminal is close to a dormer window.

Gaining access to the boxed in soil pipe would be the next place to examine.

 

[slapper]

If you are venting thro the roof then its unlikely that an AAV is fitted unless the vent terminal is close to a dormer window.

Gaining access to the boxed in soil pipe would be the next place to examine.

+1

 

[Bosswhite]

Check the light fitting in that room, the plastic fitting could be getting hot !