Here’s a call that might be interesting, but i have questions for some of the more experienced inspectors.
I’m a full time fireman and a part time home inspector. Last night we had a call for the CO detector that was going off. The weather was just above freezing with rain/sleet, very humid, the high efficency furnace was only 2 years old. The intake/exhaust was located in the rear corner of the house with a 5 ft wood fence on one side and the AC compressor on the other, the intake was facing down about 12 inches from the ground and the exhaust facing out. We had a low reading with the meter about 10 ppm in the house, nothing to be that concerned about. I went out to the back yard to check the intake/exhaust when my meter jumped to 800 ppm at the back door, the air was heavy, there was a sour smell and my eyes started to burn, and depending on how the wind was blowing the meter reading would change.
The reading at the intake pipe was 500 ppm depending on the wind which meant that the furnace was drawing up contaminated air. I believe that the high humidity had a part in suspending the CO in the air. I came to realize that some of the exhaust in the house was coming from the back door.
The questions are:
- Is this more common than I realize? Has anybody else ever heard of this?
- Since the reading was soo low in the house can CO be reburned by the furnace since it was in the intake air?
- Does the exhaust normally have a smell like this?