George E. Cawthon wrote:

You are way too paranoid. So you deal with the carbon monoxide from
the furnace. Now that it is fixed where are you going to get CO, so
why do you have 3 detectors? Did you have a detector before the
furnace was fixed? if not why didn't you die? The fact is that
deaths due to CO are relatively rare in homes and mostly confined to
people doing very stupid things and the small remainder are due to
extremely poor maintenance of fuel burning furnaces.

I knew someone on the ground floor of a NYC apt building who died of CO.
Last year, I woke up at 2 AM to my CO detector alarm and a headache and
went downstairs and found I had shoveled a few red coals out of the
woodstove and into the ash bucket...

...Most houses leak a minimum of 10 percent volume per day, which
avoids any CO2 build up.

Most houses leak a min 10% per HOUR, but maybe not, on a still day
with equal indoor and outdoor temps. A 60% humidistat or 0.1% CO2
detector might turn on a vent fan as needed.

...there are CO2 detectors available at a cost no much greater than
a CO detector.

Where? The cheapest I've seen is about $500, vs a $40 CO detector.
There may be a cheaper Japanese CO2 detector in the near future.

And of course, you could have just bought one CO detector and waited
and go a CO and a CO2 combined detector for less than the cost of the
other two CO detector you bought. These are becoming more and more
common in the big box stores...

Can you name one? :-)

Nick