Radon fan replacement in Calgary

What does the fan do in a radon system?

It creates the pressure difference that the whole method relies on. Without it, the pipe through the floor is only a pipe.

Health Canada describes sub-slab depressurization as the most common and effective way of reducing radon, and gives sealing or added ventilation only a limited effect by themselvessource. The word that matters is depressurization. A fan on the pipe draws air from the soil under the slab, a sump lid or a crawl space membrane, and sends it outdoors. That keeps the ground side at a lower pressure than the basement, so soil gas travels to the pipe and not into the room.

The fan runs day and night, in every season, for as long as the house stands on that soil. It is the only component with a motor and bearings, so it is the part that eventually needs attention. Some people call it a radon pump. It is the same device.

The drawing shows the layout Plinio Neto installs as standard, with the fan on the pipe inside the basement and the manometer below it. The photo shows a fan of that kind mounted beside an electrical panel. A fan placed indoors like this is easy to hear, easy to reach and easy to swap.

What are the signs that a radon fan is failing?

A changed gauge, a changed sound, an alarm or a rising reading on a monitor. One of these on its own is a reason to look closer. It is not yet proof that the fan is finished.

Sound deserves its own note. Every fan makes some, and the level you heard on installation day is the baseline. What counts is a change. Our guide to radon fan noise and what causes it separates the harmless sounds from those that point to the motor.

How do I read the manometer?

Compare the two liquid levels with each other, and then with the figure written on the label. A U-tube manometer on the pipe indicates that the system is working when the liquid stands higher on one side, which reflects the pressure difference the fan createssource.

The installer normally marks the start-up reading on the tube or on the system label. That number belongs to your house. A neighbour's gauge may sit higher or lower and be perfectly normal, because the soil and the fan are different. What you are watching for is movement away from your own mark.

Two limits are worth knowing. First, the gauge is not a radon meter. It shows suction in the pipe and nothing about the air in the room. Second, the gauge can mislead when the small tube that links it to the pipe has slipped off or the liquid has evaporated low. A level gauge with a fan that is clearly running and moving air usually means the tube, not the motor. More detail is in our guide to the manometer and alarm.

What can I check myself before booking a visit?

Power, the outlet and the gauge tube. These are the simple causes of a silent fan, and none of them needs tools.

1. Look at the electrical panel for a tripped breaker, and reset it once only.
2. Find the switch or plug near the fan. Fans are sometimes switched off by a tradesperson or unplugged to free an outlet.
3. Put a hand on the pipe beside the fan. A running fan gives a faint, steady vibration.
4. Go outside and look at the exhaust opening. Snow piled against the wall, leaves, a nest or a child's toy can block it.
5. Check that the manometer tube is still pushed into the pipe at one end and the gauge at the other.
6. Note the gauge reading and the fan's model label, and take a photo of both.

Stop there. A breaker that trips again points to an electrical fault in the motor, and the fan should stay off until it has been looked at. Do not open the fan housing or loosen the couplings while the system is under suction. The photo of the label and gauge is useful: it lets the installer arrive with a suitable fan.

Is the problem the fan or the rest of the system?

Often the fan, but not always. A healthy motor cannot hold suction if air is leaking in somewhere else, and a new fan will not fix a leak.

That last row is the one a simple swap cannot solve. If the level was never brought down properly, the fault lies in the design and not in the age of the motor. Work of that kind is described under radon system inspection and repair.

How is the replacement fan chosen?

By matching it to the house, not by picking the strongest one on the shelf. Fans differ in how much suction they can develop and how much air they can move, and those two abilities trade off against each other.

The ground under the floor decides which matters more. Coarse gravel lets air through easily, so the fan has to move volume without needing much suction. Dense clay or sand gives up very little air, so the fan must pull hard to move a small amount. A fan built for the first job performs poorly at the second, and the reverse is also true.

When the old system worked well, the starting point is the model on the old fan's label and the reading on the gauge. A like-for-like replacement usually restores the original performance. When the old system was marginal, the installer measures suction at the pipe and at test points in the slab before choosing, and may recommend a different model. Pipe diameter, the length of the run and the number of bends are part of the same calculation, since each adds resistance the fan has to overcome.

Manufacturers publish their own terms of coverage for each model. Keep the invoice and the model number, and read the manufacturer's document for what it says. We do not restate those terms here.

What happens during the replacement visit?

The old fan comes out between its two couplings and the new one goes into the same space. In the standard indoor layout no pipe has to be cut.

1. Diagnosis. Power, gauge and airflow are checked to confirm the fan is the cause.
2. Isolation. The circuit is switched off and the fan is disconnected.
3. Removal. The couplings are loosened and the fan is lifted out; any water in the housing is drained.
4. Inspection. The pipe on both sides, the outlet and nearby seals are examined while the system is open.
5. Fitting. The new fan is set in the correct direction of flow and the couplings are tightened.
6. Start-up. Power is restored and the manometer is read against the original mark.
7. Record. The label is updated with the new model, the date and the new reading.

Health Canada recommends that radon work be done by a professional certified through the Canadian National Radon Proficiency Program (C-NRPP)source. Fan replacements arranged through Calgary Radon Pro are done by Plinio Neto, C-NRPP certified mitigation professional (CRMT-202966). The credential is personal to him and is listed in the C-NRPP online directory. The standard behind the work is CAN/CGSB-149.12-2024, the Canadian document on radon mitigation options for existing buildingssource. It does not matter who installed the original system.

What goes into the price of a fan replacement?

The fan itself, the labour to exchange it and the check afterwards. The fan model is the largest variable, followed by how easy the old one is to reach.

A fan in a basement mechanical room is quick to change. One mounted in an attic, or high on an outside wall, takes longer because of access. Extra work found during the visit, such as a failed coupling, a section of pipe that holds water or a missing gauge, should be priced and explained before it is done. Our Calgary mitigation cost guide shows how a fan replacement compares with a new system.

How urgent is a stopped fan?

It is not an emergency, and it should not be left for a season either. With the fan off, expect the radon level to drift back toward what the house measured before the system existed.

Health Canada lists an increased risk of lung cancer as the only known health effect of radon, and describes that risk as long-term, not immediate, depending on the level, the length of exposure and smokingsource. That is why the concern with a stopped fan is the weeks and months it stays off, and why a long interruption is worth avoiding, above all in a house that tested far above the guideline to begin with. For homes above 200 Bq/m³, Health Canada's advice is to mitigate within one year, and sooner when the level is highersource. A house whose system has quit is, in practice, back in that position.

So book the visit, and resist the urge to open windows in January as a substitute. If you have the original test report, find it. The pre-mitigation number tells you how much the fan was doing.

Why does a stopped fan matter more in a Calgary winter?

Because the cold months are when houses here pull hardest on the soil. Health Canada notes that radon is drawn in where indoor air pressure is lower than the pressure in the ground, and that the stack effect increases entry during cold monthssource. It also describes the heating season, with windows closed, as the time when indoor radon tends to be highestsource. A fan that fails in November therefore leaves the system off through the months when indoor radon tends to be highest.

The standard layout helps with access in that season. The Canadian mitigation standard allows a system to vent above the roof or through a side wall near ground level, and says the side-wall arrangement shall be favoured in cold weather areassource. With the fan indoors and only the outlet outside, a replacement is a job done standing on a basement floor, whatever the weather. Systems built by other installers with the fan in an attic or on an exterior wall can be serviced too. The visit takes longer, and the assessment may raise the option of moving the fan inside.

Winter is also when the outlet most needs a glance. After heavy snowfall or drifting, walk round to the side of the house and make sure the opening is clear.

How is the new fan's performance confirmed?

In two stages: suction on the day, radon afterwards. The manometer reading at start-up shows the fan is pulling as it should. Only a measurement of the air shows what that has done to the level.

The installer takes a short verification reading once the new fan has been running. A consumer monitor of your own, if you keep one, can follow the trend after that. C-NRPP tests consumer-grade electronic radon monitors and publishes the models it approves; it points out that they cannot be professionally calibrated, and advises leaving one in place for at least 3 monthssource. Treat a monitor as a trend indicator, not as the record for the house.

The record comes from a long-term test, done with an independent laboratory kit that you place and mail yourself. We do not grade our own work. Health Canada recommends a measurement lasting 3 to 12 months and no shorter than 91 dayssource. It also recommends retesting a home with an active system every 5 years, and after renovations that affect the structure or ventilationsource. In our view a fan change is a sensible moment to restart that clock. The figure is then read against the Canadian guideline of 200 Bq/m³, the annual average above which Health Canada recommends corrective actionsource, keeping in mind that lower is better and no level is considered risk-free.

The procedure is set out under post-mitigation radon testing. To understand a number you already have, use the test result checker or read radon levels and what the guideline means. For everything else about how these systems are designed, start at radon mitigation for Calgary homes, or see rough-in activation in newer houses and sump pit mitigation systems for the two closest services.