Carbon monoxide is colorless, odorless and tasteless. You won't be aware that it's there - but long exposure to small amounts, or even short exposure to large amounts can result in illness or even death.
The only way to be sure that it's not a problem for you and your family is to use a specially designed carbon monoxide detector. These detectors cost just a few dollars and will give you complete peace of mind.
You will probably want to get more than one and position them in a number of strategic locations throughout your family home.
The monitors are very easy to use. You just have to put the batteries in and put them in whichever location you want - nothing to it. Don't forget to check the batteries from time to time of course.