"curmudgeon" wrote in message
...
I agree with Deke.
Two years ago a serviceman out on a "tune up" call reported a crack....and
I could see what looked like a crack.
But I didn't have the money for a new furnace, so I went and bought two
hi-end Co2 detectors instead...to tide me over.
In two years they have NEVER gone off!

Those things are worthless then,
a CO2 detector should be going off pretty often if your still breathing.

I myself bought a CO dectector.

Dave