Question: I have 2 sets of gas logs installed in masonry fireplaces. We have propane heat in our home. Both sets of logs seem to get excessively 'sooty" and at times you can even smell the fumes. Sometimes we turn them off because of the fumes. I have searched you pages here and saw a lot of interesting Q&A but nothing addressing this one. What can I check? Answer: LP does make a lot more soot than natural gas. It's not the soot that worries me- as much as the smell. If you can smell it means your chimney is not drafting upwards. This is a chimney problem- not the fault of the logs.There are many potential causes of poor draft- and just as many solutions. Check out our articles on chimneys at the info link below.