Safety Siren Pro Series3 Radon Detector

The Safety Siren Pro Series3 is one of America's longest-serving residential radon monitors, trusted by homeowners and real estate professionals since the late 1990s. Unlike battery-powered or app-connected devices, this unit plugs directly into a standard 110V wall outlet and provides continuous digital readouts of your home's radon levels — no smartphone, Wi-Fi, or ongoing subscription required.

After an initial 48-hour sampling period, the unit displays both a short-term average (updated every hour) and a long-term average that tracks up to 12 months of historical data. If radon rises above the EPA's recommended action level of 4.0 pCi/L, the built-in audible alarm sounds to alert you immediately, day or night.

The plug-in design gives you flexibility in placement. The EPA recommends testing in your lowest livable area — typically a basement or ground floor — away from drafts, exterior walls, and HVAC vents. The Safety Siren can be placed on any shelf or tabletop near an outlet at about waist height for optimal sampling. When you unplug the unit (such as after radon mitigation work), it resets and starts a fresh measurement cycle from zero, making it easy to verify whether mitigation was effective.

Where the Safety Siren excels is in its simplicity. There are no apps to configure, no accounts to create, and no monthly fees. The digital display is always visible, and the alarm is loud enough to be heard from adjacent rooms. For homeowners who want dependable, always-on radon monitoring without any tech complexity, the Pro Series3 has earned its reputation as the no-fuss gold standard.