Yelp's cost guide says a smoke test typically costs $250 to $300 and takes an hour or less. A plain test of one open-access house lands near that; a big or awkward property climbs. A plumber blows non-toxic smoke into the drain system and watches where it escapes, which shows cracks, open joints and missing caps. Other work we send plumbers to is listed on the Del Amo Plumbing home page.
What should a smoke test run me here?
Yelp's guide says $250 to $300 for a smoke test of an hour or less. That is a national figure, not Torrance-specific, and a larger or harder-access property costs more, so let a written quote settle it. Ask what the quote covers, and what it leaves out, before you book.
| Source or scenario | Guide figure |
|---|---|
| Yelp, quick test | $250 to $300, under an hour |
| Larger or harder-access property | quoted after a look |
Scope drives the number: how many lines are tested, whether the roof must be reached, how big the house is, and whether walls, cabinets or crawl spaces must be opened. Ask when you book whether any of the test fee comes off a follow-up repair.
What does a smoke test actually find?
It finds places where the drain, waste and vent system is open to the air: cracked or broken pipe, loose joints, a missing cleanout cap, a vent that has come apart in the attic, or a toilet seal that is not tight. Smoke shows at the leak, so the plumber can see where the problem is.
The test is a common answer to the question behind sewer smell. If your home has a smell that no fixture explains, the cause is often a dry trap or a broken vent, and smoke can point to either. The cheaper checks to try beforehand are in chasing a sewer smell out of a house. A smoke test does not see cracks buried under a slab unless smoke escapes to the surface, and for those, a drain camera is the better tool, priced on our plumbing inspection cost page.
What happens during the test?
The plumber seals the system at the roof vent or a cleanout, runs a smoke machine into the pipes, and walks the house and yard looking for wisps. Expect it to occupy an hour or two. Smoke is non-toxic and has no lasting smell, but tell your household and neighbors beforehand.
Pour water into every floor drain and unused trap first, so smoke is not leaking through a dry seal that has simply evaporated. Tell the plumber about any pets or people with breathing conditions. A smoke alarm could trip if smoke enters the house, so ask where alarms are and whether the plumber suggests covering them. Access to the roof or attic is part of the job, and a locked gate or a blocked vent adds time.
Is a smoke test worth the money?
Yes when the symptom is a smell, a suspected broken vent or a drain that gurgles, and when you need to know where air is escaping. It is not the right test for a water supply leak, a slow drain or a gas problem, and a different method suits each of those.
A pressurized water line that leaks needs leak detection instead, priced under plumber leak detection cost. A clog calls for a snake or camera. Where a smoke test shines is sparing you from opening walls to hunt a vent break. Postwar Torrance houses can have old roof vents that crack, and smoke shows those from outside within minutes.
Does a smoke test check gas lines or heating equipment?
No. A drain smoke test only covers the waste and vent pipes. Gas piping is checked with a pressure test by a contractor qualified for gas work, and a water heater or furnace vent is checked for draft and leaks separately. A clean smoke result says nothing about gas safety.
Treat a gas smell as an emergency: step outside without flipping switches, then ring SoCalGas, 1-800-427-2200, with 911 for real danger. Sewer gas and natural gas can smell alike to some noses, so when in doubt, act as if it is gas. We can arrange a plumber for either kind of check.
Which questions belong on the booking call?
Find out what the fee covers, how many hours it includes, if the finding comes in writing, if part of it comes off a repair, and if the plumber has a contractor license issued in California. Check also if a roof visit is included, since it can change the price.
A written finding that names where smoke escaped, with photos, is more useful than a spoken one, especially if you are selling a house or filing a claim. Torrance Building and Safety treats sewer and drain repairs as permitted plumbing work, so settle who pulls the permit should the test lead to a repair. A request begins on the quote form.
Common questions
Is the smoke harmful?
Plumbers use a non-toxic smoke made for the purpose, and it does not leave a lasting smell. It can set off smoke alarms, and people with breathing conditions should stay out of the room while it is in the system. Request the product data sheet from the plumber.
Is it a quick job?
A simple house is often finished in an hour or two, and Yelp says a basic test takes an hour or less. A large property, several drain lines or a roof that is hard to reach takes longer. Add time if the plumber must cap and seal every opening.
Will a smoke test find a leak under the slab?
Not reliably. Smoke shows only where it escapes into the open air. A crack deep under a slab may let smoke out into soil without any wisp appearing. If you suspect a buried line is damaged, a drain camera or a leak detection visit is a better choice.
Can I do a smoke test myself?
Smoke candles for pipe testing are sold at hardware stores, but without the machine, sealing equipment and roof access, a DIY test is unreliable, and burning anything in a drain risks fire alarms and damaged pipe. A plumber's test is safer and gives a written result.
Is a smoke test needed for a home sale?
Not as a rule. Buyers more often order a sewer camera inspection, which looks at the buried line. A smoke test comes up when there is a smell, a suspected vent problem or a repair to confirm. Ask your agent or inspector which test the lender or buyer expects.
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