One of our clients was having an issue with their chimney over the winter during heavy snow. Every time snow would melt on the roof, they would get a leak in the house. He formulated a plan to get on the roof, check out the top of the chimney and investigate, when his wife suggested he call us instead.
When we got to this estimate, we set up our ladder and safety equipment and climbed up to find the issue. Upon inspection, we found the chimney lacked a flue from the crown to about 4 feet in - meaning that the gasses couldn't directly vent out correctly. It also meant that snow would fall into the chimney and as it melted, would cause a leak. So during those heavy snowfalls, the snow was going around the flue and melting enough to cause damage in the house.
The proper fix was to tear the crown off, install a continuous flue and reinstall a new crown. We sealed up some of the holes in the flashing using silicone and we are confident the leaking is no more. Our customer’s wife was spot on. Have a professional check it out so you don’t risk getting hurt.