Chimney Liner Installation in Rockford, IL

What a chimney liner does

A liner is the flue inside the chimney. It has three jobs: contain heat and exhaust so they do not reach the masonry or the framing around it, keep combustion gases moving up and out, and resist the acids and moisture that exhaust carries. In many older houses the liner is a column of clay tile set inside the brick. Clay is durable but brittle, and the joints between tiles can open. A damaged or mismatched liner lets heat, smoke and carbon monoxide leak into the walls.

A liner is picked for the appliance on the other end. A wood fireplace, a wood stove, a gas furnace and a gas water heater do not need the same flue. Putting the wrong size or type behind the wrong appliance causes poor draft, condensation or a hot chimney. The liner guide covers how to tell if you need one.

Signs you need a liner

• A camera inspection shows cracked, missing or offset clay tiles, or gaps at the joints.
• You are adding or changing an appliance: a new insert, a stove, a high-efficiency furnace or a new water heater on the same flue.
• Flakes of tile or crumbling mortar are in the firebox or the clean-out.
• The chimney had a fire. The flue should be inspected before use, and often relined.
• The inspection report finds the flue is too large for the appliance and exhaust is cooling and condensing before it exits.
• White staining, peeling paint or moisture on the chimney wall inside the house.

CSIA recommends a Level 2 inspection before relining, and a camera scan is how the problem is found. See chimney inspection.

Liner types

Stainless steel

A flexible or rigid stainless tube is lowered down from the top of the chimney. It is the usual fix for a wood stove or insert, and for a furnace or water heater flue that is too big. HomeGuide, chimney liner cost (updated February 9, 2026) prices a stainless reline at $900 to $3,800.

Clay tile

Clay tile is the original liner in many older chimneys. Replacing it means breaking out the old tile and setting new sections. It is long-lasting but slow work.

Cast-in-place

A cast-in-place liner is formed inside the existing flue with a lightweight cement mix. It seals and smooths a damaged flue without removing the old tile. HomeGuide, chimney liner cost (updated February 9, 2026) prices clay or cast-in-place liners at $2,000 to $7,000.

How a liner is installed

1. A camera scan confirms the flue path, the size and the condition. The technician matches the liner to the appliance.
2. The flue is cleaned so the liner can pass freely.
3. For a stainless liner, the tube is lowered from the top and connected to the appliance at the bottom, or to a tee for a furnace.
4. The top is sealed with a top plate and a cap so water cannot run between the liner and the masonry. See cap installation.
5. The appliance connector is checked, and the draft and the seal are tested.

What a liner costs

Angi, chimney liner cost (updated September 21, 2026) puts liner work at $1,500 to $5,000, with an average of $2,500. It notes labor at $400 to $1,250. HomeGuide, chimney liner cost (updated February 9, 2026) gives $1,500 to $4,000 overall, a stainless reline at $900 to $3,800 and clay or cast-in-place at $2,000 to $7,000. Chimney height, the liner type and diameter, the number of flues and how hard the chimney is to access all move the price. See the cost page for the other jobs.

Furnace and water heater flues in Rockford

Winnebago County heats with gas: 83.5% of county homes (Census ACS 5-year), against only 169 that heat with wood. In Rockford the gas share is 82.4%. In many older houses the furnace and water heater vent into the old masonry chimney. When a new, high-efficiency furnace or water heater is installed, the exhaust is cooler and wetter than the old appliance's. An oversized masonry flue can let that exhaust condense and attack the tile and mortar. That is why liners are a common part of a furnace swap. The furnace and water heater liner guide goes through it.

Rockford's Property Standards say all fuel-burning appliances must connect to an approved chimney or vent. Loves Park's property maintenance amendment (Ord. 4090-16) says the same. A flue that has deteriorated is not an approved vent, which is the code reason a chimney gets relined when an appliance changes.

Rockford's median home was built in 1963, and 22.4% of its housing units date from before 1940, so a lot of the flues here are original. Municipal pages we read do not name a liner as permit-free or permit-required. Call your building office first: in Rockford, Loves Park or the county. A new appliance connected to a liner is permitted mechanical work in Rockford and Loves Park.

Carbon monoxide

A failing flue is a carbon monoxide risk, and Illinois requires alarms where fuel is burned.

The Consumer Product Safety Commission names furnaces, water heaters, chimneys, flues and vents in its yearly inspection advice. A liner is not a substitute for an alarm. See the carbon monoxide alarm law guide.

What the camera should show before a quote

A liner quote without a camera scan is a guess. Before you sign, you should have seen the inside of the flue. The video should show the tile joints, the condition of the mortar, any offsets, cracks or gaps, and anything blocking the flue. It also shows the size, which decides the liner diameter. If the technician cannot show you the scan, ask why. CSIA recommends a Level 2 before relining for just this reason. The inspection page explains what the levels include.

Sizing a liner to the appliance

The liner has to suit the appliance. Too large and the exhaust cools and does not draw well. Too small and it cannot carry the load. A wood stove or insert has a flue outlet of a certain size. A furnace or water heater has a vent size in its installation instructions. The person who installs the liner should know the appliance's requirements and match them. If a new furnace or water heater is going in, get the HVAC contractor and the liner installer to agree on the size before either orders anything. Tell the chimney company which appliance goes on which flue.

Insulation, top seal and warranty

Some liners are insulated, which helps keep exhaust warm and the flue clean. The top of the liner has to be sealed to the crown or the flue with a top plate or a cap, so water cannot run down the gap. The connection to the appliance has to be tight. Ask what the manufacturer's warranty covers, how long it runs, and what the installer's own warranty adds. Get both in writing. Illinois requires a written contract over $1,000, and every price in Angi's liner range is above that line.

A fireplace you rarely use

Owners of occasional fireplaces ask whether a liner is worth it. If the camera shows a sound clay flue and you burn a few times a year, you may not need one. If it shows gaps and you plan to burn, the risk is the gaps. If you only plan to run gas logs, ask the installer what the unit needs. The liner guide gives the decision steps.

Questions to ask before you hire

• What did the camera scan show, and can I see the video?
• What liner type and diameter do you recommend for my appliance, and why?
• Is it insulated, and is the top sealed?
• Does the quote include the cap, the appliance connector and the permit if one is needed?
• What is the warranty, and is it in writing? The Illinois contract rules apply over $1,000.

Tell us which appliance the flue serves and what the inspection found. We reply with a price first.