Yes!  The original CO/PRO had one CO sensor and was designed for single-stage furnaces.  The CO/PRO 2 was designed with two CO sensors to actively monitor for CO in the ambient air and duct air simultaneously.

Great question!  Pressing the button on a traditional CO detector tests the battery and the audible alarm. To test if the CO sensor is still working, a can of CO gas should be sprayed into the detector to see if it alarms.  These tests should be performed frequently to make sure the CO detector is working.  Unfortunately, most people haven't tested their devices since they originally installed them.

The CO/PRO uses an electrochemical sensor, and our electronics perform a daily self-test to verify if the CO sensor is still active.  This takes a tremendous burdon off of the homeowner and gives them peace of mind.

Yes - you still need CO detectors in your home!  The CO/PRO does NOT replace the legal requirement to have CO detectors in your home.

There are many different sources of CO besides the furance and water heater. CO detectors are required by state law and always verify with your state for their specific requirements.   

Unfortunately, no.  We are investigating a method that will work with all tankless water heaters and will update our website soon.

18-22 gauge wire is recommended.  For the connection between the CO/PRO and the furnace, we recommend using something like 18-gauge 4-wire.  For the connection between the CO/PRO and water heater, we recommend 18-gauge 2-wire.  

In the link between the CO/PRO and the furnace, two of the 4 wires are used for powering the CO/PRO from the furnace's 24V transformer, while the other two are used for interrupting one of the power being delivered from the transformer to the furnace's control board.

No.  We chose to leverage the power of the Smart Home thermostats to inform the user about the status of their fuel-burning appliance.   Smart home thermostats have WiFi and usually have battery backup capability.  If the power to the furnace fails, these thermostats should provide an indication to the user about the loss of power to the furnace.   

If we continue to get inquiries about WiFi, we'll consider adding it to one of our future releases.

Most electronic components (microprocessors, resistors, capacitors,..etc.) come from countries outside the United States.  The Federal Trade Commission (FTC) has rules on what percentage of the product is made in the US to be able to say "Made in the USA."    We hope one day when the economy changes that we can say we are 100% Made in the USA!