A weird smell coming from the drain isn’t a rare occurrence, but it means that something, somewhere in your plumbing needs your attention. From a simple clogged drain to a potentially serious problem, this article describes 3 strange plumbing smells, what causes them and how to resolve them.
Mould or Mildew
Musty smells stem from the growth of mould, which thrives in a damp environment. Although not all mould growth and smells originate from plumbing, it can be indicative of a plumbing leak in your system if also accompanied by trickling noises, damp patches around the home, a change in water pressure or a sudden spike in your water bill. It is important not to ignore this smell, as prolonged inhalation of the mould spores can cause respiratory problems for you and your family
If you suspect that a leak is the cause of that mouldy smell, your best option is to call an experienced plumber to do a leak detection service on your home. Using high tech tools such as thermal imaging they can find the source of the leak non-invasively and advise on the best solution.
Rotten Eggs
This is an interesting plumbing smell as it could have multiple explanations.
The simplest is that dirt has built up in the drain and caused a clog or partial clog – when bacteria feed on this it can produce a gas called hydrogen sulphide which produces the rotten egg smell.
Another cause, particularly if this smell is coming from a sink is an issue with the P trap – the P- or U- shaped part of the pipes which are designed to hold water, which prevents gas from flowing back up the plug hole. Some problems include underuse of that sink meaning that the water in the P trap dries up so there is nothing to trap the gas. Or this part of the piping has become clogged.
There are some further causes of rotten egg smells including contaminated water. Also, if you notice the smell only happens when you run hot water, this could be a reaction between the hot water and the anode rod in the heater.
A good action plan to get rid of eggy smells is first to try unclogging the drain and seeing if this resolves. If the smell persists, a call to the plumber to come and investigate properly is the next step!
Decay / Garbage Smell
If you detect a trash-bin type smell, this is often due to some trapped organic matter within the plumbing which bacteria have started to feed on. This happens usually if there is old food debris trapped somewhere such as kitchen sink drains or garbage disposals. Another explanation could be something known as biofilm, which is an accumulation of soap scum, skin oils and other residue.
In order to get rid of this smell, as with the other issues it is first important to address the root cause otherwise you will only be masking the smell, or it will reoccur in the future. Make sure that the garbage disposal is being used appropriately, and the clog is removed. Then to neutralise the smell, you can use a drain cleaner, or quite often some baking soda or white vinegar will do the trick.
As always, if you are concerned about your plumbing, the best thing is to call a plumber to come and investigate – they are professionals and will be much more efficient at diagnosing and fixing any issues, plus things like inspecting your drains using a manhole lifter for safe access may be best left to them. These will give you and your family peace of mind.