There is a sewer smell in the house
The most common cause is a dry P-trap in a drain that has not been used recently, which lets sewer gas up through the fixture. Run water into every drain, including guest bathrooms and floor drains, and wait a day. If the smell persists, the cause is usually a venting problem or a failed seal rather than a trap.
Do this first
- Run water into every drain in the house, including ones you never use.
- Pour a jug of water into any floor drains, in the garage or laundry especially.
- Check whether the smell is in one room or throughout.
- Wait a day. If it is gone, it was a dry trap. If not, call and tell us where it is worst.
What it usually is
- A dry trapWater in an unused P-trap evaporates, especially in a Houston summer with the air conditioning running.
- A failed toilet wax ringSmell around one toilet, sometimes with movement in the bowl base.
- A venting problemBlocked or improperly terminated vent, which pulls traps dry as fixtures drain.
- A broken drain lineLess common, but a cracked line in a wall or under the slab lets gas escape.
When to call, and when it can wait
If you do need us
Rule out dry traps first
We will tell you to do this before booking, because it costs nothing and often solves it.
Locate where it is strongest
One room points at a fixture. Throughout points at venting.
Test rather than guess
Where needed, we test to find where gas is escaping instead of replacing parts hopefully.
Repair the actual cause
Wax ring, vent, or line — whichever the testing identified.
Houston note
Houston summers make dry traps a seasonal complaint. Guest bathrooms, garage floor drains, and rarely used showers are the usual suspects. Running water into them monthly is free and prevents the most common version of this call entirely.
Related problems
What moves the price
- CAUSEA wax ring is small. A vent or line repair is not.
- ACCESSWhether the vent or line can be reached without opening finishes.
- SCOPEOne fixture versus a system-wide venting issue.
Questions about this
Is sewer gas dangerous?
It is unpleasant and at high concentrations it is a health concern, which is why a persistent smell should not be ignored. It is also not the same as natural gas. If what you smell is gas rather than sewage, leave and call 911 or the utility instead.
Why does it only smell in summer?
Air conditioning dries the air and increases evaporation from unused traps, and guest bathrooms go longer between uses. Dry traps are genuinely more common in a Houston summer.
Could it be the water heater or the AC?
An air conditioning condensate line that ties into the drain system can be a path for odour if its trap is dry or missing. It is worth checking, and it is a good example of why we want to know where the smell is strongest.
Not sure how urgent it is?
Describe what is happening and we will tell you straight: call an emergency out now, book it for today, or leave it until the week.