Manometer Readings on a Radon System, Explained
A manometer is a small, typically U-shaped tube gauge mounted on the radon system pipe that shows the vacuum, the negative pressure, the fan is creating in the sub-slab area. A reading with liquid clearly displaced from level confirms the fan is running and creating suction; a reading back at level or near it, with the fan otherwise appearing to run, usually indicates a problem such as a blocked pipe or a failing fan.
This is the single easiest maintenance check a homeowner can do without any equipment or expertise beyond glancing at a gauge, which is exactly why installers point it out at the end of a job. It will not tell you the radon concentration itself, only whether the system is actively working to reduce it.
See our page on warning signs a radon system is not working for the fuller list of things worth checking beyond the manometer alone.
Common questions
How often should the manometer be checked?
A quick visual check every few months is reasonable, along with a check any time you happen to be near the pipe run, such as in a basement or garage where it is commonly installed.
What should I do if the reading looks off?
Contact the installer or a certified mitigation contractor rather than attempting to diagnose the fan yourself; a manometer reading tells you something changed but not specifically what, and troubleshooting a sub-slab system properly benefits from the same expertise as the original install.
Have a number you want read?
Tell us the result and your town in York County, or call and read it out. We will tell you what it points to and what a system would involve in a house like yours.
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