Chimney and fireplace service in the Fox Valley and McHenry County

Out here the lake does little to soften the winter. NOAA's 1991 to 2020 normals give Rockford, the long-term inland station to the northwest, about 136 nights a year at or below freezing against about 121 at O'Hare, and about 11.5 nights at or below zero against 6.5. Subtract the days that never rise above freezing and Rockford has roughly 86 freeze-thaw days a year to O'Hare's 78 (both derived). The Fox River towns lie between the two stations. Lake-effect snow rarely gets this far: in the November 2025 event that buried parts of Lake County, Rockford recorded a trace.

The river towns have old cores. In Elgin, 18.9 percent of homes predate 1940 and in Aurora 13.5 percent, about 16,300 pre-war homes between them, though the median home was built in 1977 in Elgin and 1987 in Aurora (Census Bureau, 2020 to 2024 survey). Kane County's median home dates to 1985 and McHenry County's to 1989, so outside the old centers most fireplaces are factory-built or gas. Gas is the main heat for 86.2 percent of Elgin homes and 85.0 percent across McHenry County.

What extra freeze-thaw cycles do to a crown

Every one of those cycles works on the top of the chimney. The sequence we see on Fox Valley stacks is almost always the same:

• A hairline crack opens in the crown or around the flue tile
• Melt water runs in during the day and freezes overnight, prying the crack wider
• Pieces of the crown break off and water reaches the top brick courses and the tile
• Brick faces spall and joints open, until the top of the stack needs rebuilding
• Caught at the first step, a minor crown repair runs $150 to $700; at the last, rebuilding the top few feet with a new crown is typically $600 to $1,000

Older brick in Elgin, Aurora and the river towns

In the older neighborhoods of Elgin and Aurora and along the river in St. Charles, Geneva and Batavia, the chimney is usually brick with a clay flue, and it now vents a gas boiler or furnace and a water heater. When those were replaced with newer equipment, the flue often ended up the wrong size. Elgin and Aurora also have a few two-unit buildings, 4.4 and 4.0 percent of homes, where one stack may serve both floors. We trace each flue and tell you what it serves before we suggest any work.

For the masonry itself we follow National Park Service Preservation Brief 2: the new mortar should be softer than the brick so the joints, not the bricks, take the movement. Stack tuckpointing typically runs $500 to $2,500, and a rebuild above the roofline $1,000 to $3,500.

Subdivision fireplaces from Algonquin to Oswego

In Huntley, Algonquin, Crystal Lake and Oswego, most of our calls are for gas fireplaces and for the metal tops of factory-built chimneys. A rusted chase cover lets water into the framed chase; a custom replacement typically costs $425 to $850. On the gas side, a pilot assembly usually runs $100 to $350 and a thermocouple $150 to $350. Yearly gas fireplace service is priced at the free inspection.