On a recent inspection I noted high (35ppm +)levels of CO at the heat outlets (gas forced air furnace - I’m in Canada). I was actually in the house on two different days and took readings at two different times on both days with similar results. Each reading was taken over a 15 minute time span. The seller is in denial and had the gas co come out to check. They gave a report saying no problems.
is anyone else using the tpi775 meter? have you ever suspected false readings?
is there any condition in which a furnace can give off differing levels of CO? Can the length of time the furnace has been running influence this?