Q: I have a rental house with a bathroom that has problems with sewer odor. Do you have any advice on how to address this?
A: The first suspect is the toilet. Gently try to move the bowl of the toilet. If the bottom moves even slightly in any direction, then the sewer gas is probably escaping around the wax ring that seals the toilet to the floor. If this is the case, remove the toilet and replace the wax seal. If the toilet is not a problem then check the drains of other fixtures. When a plumbing fixture hasn’t been used in a while, the traps below the drain can cry out, allowing gases to escape.
Pour a cup of water down the drain to reseal a trap. Also, clean the floor thoroughly and, if possible, ensure the bathroom has adequate ventilation and an operable window or exhaust fan.