I have a gas furnace off a 1 bedroom apt. Im the top floor so the furnace chimney goes right out the roof. On days when there is high humidity or right when it rains, Sometimes the carbon monoxide detector will go off.

Something I read mentioned that the humidity in the air might be causing the excess unburned natural gas that would usually leave through the chimney to get pocketed where the air in my apt and the humid air in the chimney meet. I know that carbon monoxide detectors are calibrated to go off when subject to very low levels of carbon monoxide. It has happened numerous times and has never actually caused a problem. Usually I just open a window and it stops going off.

Does anyone know a way to prevent this from happening on rainy days? I am going to try a taller chimney soon. I am also worried that it maybe a more severe problem than I think it is...

Thanks for your time

((It has happened numerous times and has never actually caused a problem. Usually I just open a window and it stops going off.))

One of these times it will cause a problem and then you might wind up dead.

This is not a do it yourself project. I recommend you call in a professional who has a digital snake with a 30+ foot cable and have the entire chimney scoped out.

Then they will make recommendations as to how to fix.

If you rent and the landlord does not want to do this call the board of health and burn his bottom. Landlords have been put in jail over carbon monoxide refusal to repair orders.

A taller chimney might be the answer but you still should have it looked at by a pro.