Handheld Carbon Monoxide Meter, WESHLGD Portable Carbon Monoxide Detector, High Accuracy 3-in-1 CO Gas Tester Alarm Monitor(CO Value, Temperature and Humidity Display) for Home/Kitchen/Hotel/RV

I wanted to double check what a HVAC technicians review of my furnace found. He recommended a Heat Exchanger replacement because it looked faulty and he had taken pictures of discoloration at some joints; or otherwise replace the whole furnace. It was 12 years old. He said CO reading was 33 PPM (boarderline reading), and I decided to call another company because of the cost $4000 for Heat Exchanger on $9800 for Furnace.So I quickly called another HVAC company to review furnace and they said it was A OK. Also, ordered this meter and it read 0 PPM. Totally Good.... I was wondering why he was closing a hole in the combustion exhaust (maybe he took the CO reading there??)

Item arrived early

Manufacturer documentation states the device will start to react at 200ppm with the alarm set to 1000ppm (default). Purchased one, and checked this device against a know concentration of 20ppm CO. The device continued to display "0ppm".Please look at the attached photo listing NIOSH warnings for various exposure limits. assuming that the manufacturers claims are correct, then this device might give a CO warning before death, but probably after one has passed out from exposure. So, it is worthless.

Seems to work. Only thing I do t like is it reads the temperature in Celsius only.

Being an OlGeezer X landlord having one of these to deal with the unscrupulous HVAC repair men is PRICELESS . My old meter went out and was having limit switch problems on my house . The repair tech reset the limit switch and said if it continues to trip it was probabally the heat exchanger and a $5000. bill for a new heater . The limit switch was faulty and triggering at 150 degrees instead of the rated 215 degrees . Replaced the switch for ten dollars and this little meter is reading zero CO for the last few hours . Ift you don't trust HVAC men then verify with your own equiptment . CHEAP INSURANCE .

seems cheap but its works, the price should be lower

Great for making sure furnace and gas appliances aren't leaking

Haven't identified toxicity yet