One question we get a lot is "Why is there a bad smell when I flush my toilet?" There are a number of issues that could cause a bad smell when you flush your toilet. The following are the most common of these issues:
Damaged Wax Sealing Ring
You have a wax seal ring beneath your toilet that keeps in the sewer gas that is displaced every time you flush. When that ring is damaged the gas escapes out between the floor and the toilet, causing a bad smell.
If your toilet seems to rock when you sit down, there is a good chance your wax ring is broken. Another biggie that homeowners don't realize has happened, is that by using a plunger or 'plumber's friend' the wax seal can be damaged by hydraulic pressure caused from the plunger. You can replace the wax ring by purchasing a new one at a hardware store.
Another possible cause of a bad odor when you flush is a clogged vent. When the bathroom drain vents become clogged the air has nowhere to go but into the bathroom. By clearing the vent you will allow the air to be directed through the vents properly and no longer have to deal with sewer gas every time you flush!
This is very prevalent in the winter when frost can slowly begin to shrink and close the vent pipe that extends through the roof. If you hear a gurgling at your tub when flushing the toilet, chances are the toilet is venting through the tub rather than to the outside, due to a malfunctioning vent. This problem can happen not just in winter but all year, for a variety of reasons.
A cracked toilet bowl is a bigger problem than a damaged wax seal ring or clogged toilet. If enough water leaks out of a crack it will allow sewer gas to enter your bathroom. Unfortunately a cracked toilet bowl is not easily fixed and you may need to replace the entire toilet.
Toilet cracks often occur underneath the bowl where they are not visible. Sometimes the crack will allow water to leak as well. If you replace the seal properly, and still have an odor or a water leak, this points to needing a new toilet.
Do you need help getting rid of a bad smell in your bathroom?