Cleaning the toilet is nobody's favourite job, but when you notice a lingering smell after scrubbing it with bleach is there cause for alarm? Now that you been living in your new home a few months, you have noticed a lingering funky smell in your toilet room. It does not appear all the time, but you want the situation fixed before the in-laws arrive for the Christmas holidays. There are a couple of reasons why this smell develops, so see if you can identify which one it may be from this list.

No water in the P-trap

When you look at the back of the toilet, you will notice a plumbing pipe that dips down and then rises back up (in the shape of a small U). When you flush the toilet, a small amount of water stays behind in the P-trap. The purpose of this water is to form a seal between the gases in the sewer below your home and the open air in your home.

If the toilet in your home is recently unused, for example, you've been away on holiday, the water in the P-trap evaporates and lets the sewer smell into your house. Alternatively, if the P-trap has a crack in it and there is a small leak, again there is no longer a seal to keep the smell out. To test if your P-trap is empty, flush the toilet and see if the odour reappears. If the smell comes back, or if there is a damp spot on the floor behind the toilet, then this is an indicator the P-trap is leaking, and the pipe needs replacing by a plumber.

Blocked vent pipe

If you can't see a leak near the P-trap, and the smell returns after running plenty of water, then it's time to look to the vent pipe. The vent pipe can be seen protruding from the roof of your home, and it is another plumbing mechanism to help sewer gas smells escape from your property.

Since it is currently spring, there are plenty of bird nests around, and it is possible that your vent pipe has become blocked by nesting birds. Use a ladder to climb up on your roof and use a torch to see if you can spy any blockages in this pipe. If you cannot, ask your plumber to come round and test the pipe. A plumber uses a machine which pushes smoke up into the pipe, and this smoke can help identify if the vent pipe is flowing clear.

Sometimes, the bad smell comes from under the house due to a cracked sewer pipe, but your local plumber can help you formally identify the source of your smell, and also help you get rid of it before it's time to welcome your holiday guests.