Open soil vent pipe in the attic

[DIYspanner]

I noticed the open pipe when I was in the attic this past week. Its connected to the en-suite's toilet.

Lying next to it on the insulation is an 'Air Admittance Valve' what I presume should be fitted to the top of the pipe?

The house was built in 2003.

Opinions welcome.

 

[HERTS P&D]

Has someone taken it off due to a problem?

Andy

 

[DIYspanner]

I don't know the history of the house, I bought it last year.

What would be the symptoms if the valve were not working properly?
I'm presuming smells caused by lack of venting perhaps?

 

[Madrab]

Usually if an AAV is removed is due to positive pressure in the soil system, that can be due to lack of alternative atmospheric venting in the drain/soil system or a restriction/bad design in the soil system downstream somewhere.

Toilets or basin/sink slow draining would be the usual symptom.

 

[Hugh Jaleak]

As above. Usual issue is a blockage downstream and poor draining of appliances/WC backing up and subsiding slowly when flushed. An AAV seals the pipe preventing positive pressure escaping, have to wonder if some amateur has chopped the AAV off (badly) to relieve the symptoms rather than cure the problem.

It needs replacing, to prevent your loft filling with steam and odour. Advise using a Push Fit type so it can be removed easily if need be to test things out. You may find once you have replaced the AAV, problems will manifest once again, in which case further investigation of the drainage system will be needed.

 

[dilalio]

People do this a lot because they think it's an easier and cheaper alternative way of putting an svp out through the roof.

But they don't understand the principles.