Actually, sewer gas smell in bathroom can possibly caused by several factors. Although there are a lot of sources that this sewer gas smell may come out from, but usually the main factors are the toilet, vent and drain in your bathroom. The main components of this gas are actually carbon dioxide, methane, ammonia and hydrogen sulfide. All of these components combined together and makes unpleasant smell.
Toilet trap is the first thing you may have to suspect for causing the sewer gas smell in bathroom. Remember that toilet is indeed the main common problem which causes this sewer gas to escape. In a toilet system, there is trap system which is created to prevent the sewer gar to escape into the bathroom. This trap is working with the help of water so the gas will not be able to pass through it and leak out.
If there is any problem occurred to this water level, then it may cause the escape of sewer gas. The water level can decrease in case the toilet is rarely used or you have a pet which constantly drink from your toilet bowl. One way to prevent this problem to happen is by regularly flushing your toilet so the water level will always be kept well.
The second possible source of sewer gas smell in bathroom is damaged toilet. If your toilet bowl is cracked internally, this can cause a leakage to the drain. This circumstance may cause the level of water to decrease and make the toilet trap to be unable to prevent the gas enters your bathroom. The same case can also be caused by a damaged wax ring of the toilet.
If this is also broken, then the sewer gas will leak out trough it as well. Damaged or broken toilet bowl and wax ring, unfortunately, could not be repaired so the only possible way to solve this problem is to replace them with a new one.
Another source of sewer gas smell in bathroom can be your bathroom drain or pipe system. The P trap of the pipe under your bathroom shower, tub or sink is also one of the systems to prevent the sewer gas escapes into your bathroom. If this drain or pipe is broken or damaged, then it is possible to cause the leakage of the sewer gas. The circumstance may also occur when the drains of your bathroom are rarely used so results in the seal created by the P trap.
Sewer gas smell in bathroom may also be caused by missing or clogged vent of your bathroom drains. Do not take this matter trivially because sewer gas smell in bathroom can possibly cause harm to the bathroomâ€™s usersâ€™ health. Therefore, it would be better if you try to find the source of this smell immediately once you smelled them and eliminate this sewer gas.