HSI products are Environmentally Friendly. Our CoCheck™, Carbon Monoxide Detector Tester does not have HFC or CFC. Our products do not damage the Ozone layer and do not contribute to Global Warming.

CoCheck™, Carbon Monoxide Detector Tester complies with both the Kyoto and Montreal Protocols and the California state requirements.


CoCheck™ is 100% All Natural and Non-Flammable This product contains material found in the air we breathe. Designed and packaged in a size that prevents any accidents. There is not enough CO in the product to produce any ill effects. It is safe, effective and it works! The perfect solution.

The Original Carbon Monoxide Detector Tester™ Since 1997

CoCheck™ has been updated and reformulated to an easy to use aerosol product. CoCheck™ has been used by professionals world-wide since 1997. This is the original and still the best option for test your carbon monoxide detector.

CoCheck™ Carbon Monoxide Detector Tester

.07oz (2g) Size, 5-10 tests per can

Part Number: HO-CO2
Standard Pack: 6 cases/Master Pack 22x13x10 (558.8x330.2x254mm)
Weight: 14 lbs.
SDS Sheet

UL Signaling Logo

CO Detector Test Gas Accessory For use with UL Certified FTAM Gas Detectors and/or Sensors 3WH9. For compatibility between CO Detector Test Kit and the Detector refer to E328172 Listing Card for Details.

The facts of Carbon Monoxide Testing

How a Carbon Monoxide Detector works; Carbon Monoxide is found in small concentrations in the air we breath. The detector is constantly testing the surrounding air for the presence of CO, when concentrations begin to rise and reach a set/predefined level, the alarm will sound, warning of a dangerous condition in the area. CO becomes dangerous in higher concentrations. After exhaustive testing, HSI determined that the key to functional CO testing is the length of exposure time and the level of concentration. Co-Check™, when used with Versa-Tools™ Enclosed Delivery Tools, provides an isolation of the CO chemical (concentration level) without using dangerous amounts. The convenient fiberglass extension pole allows you to place the enclosed head around the detector, brace with the pole and walk away. No standing there and holding the tools for extended periods of time!

Diag A

Diag B

To Use:
1. Connect HO-VTCO2-S Sleeve at Velcro (Diag A) and insert in the can compartment of the VT-1 Enclosed Delivery Test Head.
2. Slide Co-Check™ can into Test Head with actuator pointed toward clear plastic bowl.
3. Replace the Can Cap and screw clockwise to tighten until you hear a slight release of aerosol, back of cap counterclockwise approximate 1/2 of a turn.
4. Place VT1 Head (Diag B) around the Carbon Monoxide Tester and push up, actuating the aerosol for approximately 3 to 5 seconds.
5. Leave in place for 10 to 20 seconds or as instructed by manufacturer. If the alarm is functioning properly the alarm will sound.

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