Sewer smoke test see where the sewer odour is coming from
Does it still smell of sewage, even after cleaning and putting water in all traps? A smoke test makes the leak visible. Call 070 783 0224.
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Sewer odour is tricky: you smell it, but you see nothing. The cause is often behind a bulkhead, under the floor or in a pipe you never see. During a smoke test we blow harmless smoke into the sewerage. Where it comes out, that's where the leak is. This means there's no need for guesswork demolition.
Short answer
A smoke inspection (smoke test) is an investigation in which harmless, visible smoke is blown into the sewer system under light pressure. The smoke escapes at every point where the drain is not sealed: a loose connection, a broken soil pipe, a forgotten open connection or a dry trap. This way we find the source of sewer odour without breaking things open on guesswork.
- Intended for: sewer smell or flies without visible cause, and checking connections.
- You receive: the locations where smoke escaped, with photos and advice for repair.
- Price: € 185.95 – € 268.60 excl. VAT (€ 225 – € 325.01 incl.), including report.
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Leave your name and number and we'll call you. Prefer immediate contact? Call 070 783 0224 or message us.
When is a smoke test useful?
Always start with the simple things: run water in every trap, every sink, shower and toilet, including in a guest room or a space you rarely use. A trap that has dried out lets sewer smell through directly. Our page drain smells and the article sewer smell in the house explain this step by step.
A smoke inspection is the next step if:
- the odour persists while all traps are filled;
- the smell comes and goes, for example during strong wind, rain or when the neighbours shower;
- you smell sewer odour in a cupboard, behind a bulkhead, in the meter cupboard, the crawl space or in the loft;
- drain flies keep coming back without you finding a source;
- the smell started after renovation work: often a connection has been forgotten or not glued properly;
- you live in an apartment complex and want to know whether the problem is in your property or in the shared soil stack.
How a smoke test works
- Brief discussion and walk-around. Where do you smell it, when and since when? We look at where the drains run and where we can best introduce the smoke: via a manhole, the rodding point or a drain outlet.
- Seal off. We fill the traps and temporarily seal the roof vent and other openings, so the smoke can only escape through leaks.
- Introducing smoke. With a smoke generator, harmless smoke goes into the pipe under light pressure. This smoke is designed for this type of investigation, leaves no residue and dissipates after ventilation.
- Search. We check all rooms, including cupboards, coves, the crawl space, the meter cupboard and the loft. Where smoke escapes, we take photos and note the location.
- Report and advice. You receive a clear overview of the findings, what needs to be done to resolve the issue, and what it will cost. Small things, such as a loose coupling, we often fix immediately in consultation.
A smoke detector in the home may go off during the test. We discuss this beforehand; in a flat we notify neighbours or the property manager if necessary.
The most commonly found causes
- Open or poorly sealed connection behind a wall or bulkhead, often after renovation: an old basin drain, a relocated WC or a forgotten cap.
- Leaking joint or crack in the soil stack, for example at a coupling that has come loose or an old cast-iron pipe that has rusted through.
- Ventilation that doesn't work: an air admittance valve that's stuck, or a vent pipe that ends in the loft instead of above the roof.
- Leaking sewer under the floor, causing sewer odour to enter via the crawl space.
- Wrong connection, for example a downpipe or drain connected to the wrong pipe, so that air finds another route.
If the smoke comes from a pipe under the ground or floor, a camera inspection is sometimes the logical next step to show the damage precisely. If there's a fracture, you can read about the options under relining and sewer fracture repair.
What Does a Smoke Inspection Cost?
A smoke inspection falls within a fixed range in our price list. Where you end up in that range depends on the size of the property and the number of pipes. You will hear the price in advance.
| Item | Excl. VAT | Incl. 21% VAT |
|---|---|---|
| Smoke inspection of sewerage, including report | € 185,95 – € 268,60 | € 225 – € 325,01 |
| Camera inspection sewer drain (as follow-up) | € 225 | € 272,25 |
| Install drain (for example, properly finish an open connection) | € 75 | € 90,75 |
| Replace kitchen drain (trap with ventilation + connections) | € 516,53 | € 625 |
Guide prices from the PandFix price list (October 2026). Call-out charge is additional: €35 excl. VAT (€42.35 incl.), emergency €65 excl. VAT (€78.65 incl.). Evening or weekend: surcharge €80 excl. VAT (€96.80 incl.). Materials and extra hours only by agreement. You will always hear the price before we start.
Rental Property or Flat?
If you rent, sewer smell in the home is usually a matter for the landlord. Report it there first. If you live in an apartment and suspect that the smell is coming from the shared soil stack, the owners' association (VvE) is often the client. A smoke inspection can then help to establish whether the leak is in your property or in the communal part. You can give the report to the landlord or VvE.
Questions about a smoke inspection
Is the smoke from a smoke test harmful?
No. We use smoke that is designed for this type of investigation. It is highly visible, leaves no residue and dissipates after airing. A smoke alarm may go off; we discuss this in advance.
How Long Does a Smoke Inspection Take?
In a normal home usually one to two hours, including preparation, searching and reviewing the findings. For a larger property or multiple floors it takes longer.
What Is the Difference with a Camera Inspection?
A camera shows the inside of one pipe, for example a fracture in the sewer under the garden. A smoke test shows where the entire drain is leaking or open, even behind walls and in corners where no camera can reach. For sewer odour without a visible cause, the smoke test is often the first choice.
What Does a Smoke Inspection Cost?
According to our price list € 185.95 – € 268.60 excl. VAT (€ 225 – € 325.01 incl.), including report, plus call-out charge. Repair work afterwards is quoted separately and in advance.
Can I tackle sewer odour myself first?
Yes. Run water in all traps and drains, including in spaces you rarely use, and check that the traps are secure. If that doesn't help within a day, then a smoke test is worthwhile. More tips are in our article about sewer smell in the house.
Do you also conduct smoke inspections for an owners' association (VvE) or commercial property?
Yes. For multiple homes on one soil stack, we plan it together with the property manager, so all residents know what is happening.
