Fireplace Insert Installation Inspection

Hire a CSIA (Chimney Safety Institute of America) certified chimney sweep to perform a Level 2 inspection before installing a fireplace insert. The inspection should assess the chimney flue for cracks, deterioration, creosote buildup, and structural integrity. The flue must be the correct size for the insert (per the insert manufacturer's specifications — typically 6-inch diameter for wood inserts). Inspect the chimney cap and verify the damper can be removed or permanently opened to accommodate the liner. Any creosote buildup must be cleaned before liner installation.

1. Hire a CSIA-certified chimney sweep for a Level 2 inspection

2. Verify the chimney flue has no cracks, gaps, or structural damage

3. Check for creosote buildup — must be cleaned to Stage 1 or better before proceeding

4. Verify the flue is the correct size to accept the chimney liner required by the insert

5. Inspect the chimney cap — must be in good condition or replaced

6. Check if the damper needs to be removed or modified to accommodate the liner

7. Verify the chimney is structurally sound and properly supported

8. Get the inspection report in writing before purchasing an insert

- Deteriorated clay tile liner — cannot support a new insert without a stainless steel liner

- Excessive creosote buildup — fire hazard that must be cleaned before any work begins

- Chimney too small for the required liner size — may need to be rebuilt or use a different insert

- Existing damage hidden by surface — Level 2 inspection uses camera to identify hidden problems

Measure the existing firebox opening: width at the top and bottom, height at the left and right sides, and depth from the front opening to the back wall. Select an insert that fits within these dimensions with the proper clearances specified by the manufacturer. Verify the insert's BTU output matches the room size — a general guideline is 5,000 BTU per 200 square feet of well-insulated space, but consult the manufacturer's sizing chart. The insert must be listed and labeled to a recognized testing standard (UL 1482 for wood, UL 1973 for gas).

1. Measure firebox width at the top and bottom (fireboxes often taper)

2. Measure firebox height at the left and right sides

3. Measure firebox depth from front face to back wall

4. Record measurements and compare to insert manufacturer's required minimum dimensions

5. Verify the insert fits with manufacturer-specified clearances on all sides

6. Calculate room heating needs and match to insert BTU output

7. Verify the insert is listed to UL 1482 (wood) or appropriate standard for the fuel type

8. Check that the required chimney liner diameter matches the insert's flue collar size

- Firebox too shallow for the insert — insert protrudes past the fireplace opening, violating clearance requirements

- Insert BTU output too high for the room — overheats the space and wastes fuel

- Not measuring at both top and bottom — tapered fireboxes can be significantly narrower at the top

- Insert not listed/labeled — may not meet code and insurance may not cover fire damage

Install a stainless steel chimney liner from the top of the chimney down to the insert's flue collar. Use 316Ti or AL29-4C stainless steel liner for wood-burning inserts (more corrosion resistant). The liner must be continuous from top to bottom with no joints in the chimney cavity. Insulate the liner per the manufacturer's specifications — wrap-around blanket insulation or poured vermiculite insulation improves draft and reduces creosote formation. Seal the top of the chimney with a top plate and rain cap. Seal the bottom connection to the insert collar.

1. Remove or open the chimney damper to allow liner passage

2. Lower the liner from the chimney top down to the firebox level

3. Verify the liner is continuous with no joints or gaps inside the chimney

4. Install insulation around the liner (blanket wrap or vermiculite pour per manufacturer)

5. Seal the top with a stainless steel top plate

6. Install a rain cap on the top plate to keep water and animals out

7. Connect the bottom of the liner to the insert's flue collar

8. Seal the connection with high-temperature silicone or a stainless steel clamp

- Liner too large for the chimney — cannot pass through offsets or narrow sections

- No insulation on liner — poor draft, excessive creosote buildup, and reduced efficiency

- Liner joints inside the chimney — potential leak point for flue gases into the house

- Rain cap not installed — water enters the liner and causes corrosion from inside

Slide the insert into the firebox carefully, connecting it to the bottom end of the chimney liner as it goes in. The flue collar on the insert must connect securely to the liner — seal with a stainless steel clamp or high-temperature (rated to 600 degrees F minimum) silicone sealant. Verify clearance to combustibles on all sides per the manufacturer's installation manual. The insert should sit level on the firebox floor. Some inserts require a hearth pad extension in front of the firebox.

1. Have a helper guide the liner from above while sliding the insert into the firebox

2. Connect the insert flue collar to the chimney liner

3. Secure the connection with a stainless steel clamp or high-temp silicone

4. Verify the insert is centered in the firebox opening

5. Check that the insert sits level

6. Measure clearance to combustibles on all sides — must meet manufacturer specifications

7. Verify no combustible materials are within the required clearance zones

8. Check that the connection between liner and insert is airtight (smoke should not escape at the joint)

- Insert too heavy to slide in safely — may need additional helpers or a dolly (inserts can weigh 300-500 lbs)

- Liner-to-insert connection not sealed — flue gases leak into the room instead of going up the chimney

- Insert not level — door does not seal properly, affects combustion and glass appearance

- Clearance to combustibles violated — fire hazard that will fail inspection

Install the surround panel (also called a face plate or shroud) to cover the gap between the insert and the firebox opening. The surround must be non-combustible material (typically painted steel or cast iron provided by the insert manufacturer). Secure the surround to the insert or to the firebox face per manufacturer instructions. Install any decorative trim pieces. The surround should fit flush against the fireplace facing with no gaps that would allow room air to bypass the insert.

1. Position the surround panel against the fireplace face, centered on the insert

2. Verify the surround covers the entire gap between the insert and the firebox opening

3. Secure the surround with the provided brackets, screws, or spring clips

4. Check that the surround sits flat against the fireplace facing (no rocking or gaps)

5. Install any decorative trim pieces per manufacturer instructions

6. Verify no gaps exist where room air could bypass the insert and enter the chimney

7. Check that surround material is non-combustible (steel, cast iron, or ceramic)

- Surround does not fully cover the firebox opening — air leaks reduce insert efficiency

- Surround not secured properly — vibration from the blower causes rattling

- Using combustible trim materials too close to the insert — fire hazard

- Wrong size surround for the firebox opening — may need custom sizing or a different model

Verify the home has adequate combustion air supply for the insert. In tightly sealed homes (energy-efficient construction), the insert may starve for air and produce poor draft, smoke spillage, or incomplete combustion. Install an outside air kit if the manufacturer offers one — this draws combustion air directly from outside rather than depressurizing the living space. Check clearances to combustibles per the manufacturer's manual and local building code. If a hearth extension is required (for wood inserts, typically 16-18 inches in front of the opening), install it with non-combustible material.

1. Determine if the home is tightly sealed (modern construction, spray foam insulation, etc.)

2. Check if the insert manufacturer offers an outside air kit — install if available

3. If no outside air kit, verify that a window can be cracked or a makeup air vent is nearby

4. Re-verify all clearances to combustibles per the manufacturer's manual

5. Check hearth extension requirements — typically 16-18 inches in front for wood inserts

6. Verify hearth extension material is non-combustible (stone, tile, concrete board)

7. Check that no combustible flooring, mantels, or wall materials are within the required clearance zones

8. Install carbon monoxide detectors in the room and on each floor of the home

- Tight home with no outside air supply — insert causes negative pressure, backdrafting, and smoke spillage

- Kitchen exhaust fans or dryer running while fireplace operates — competes for combustion air

- Hearth extension too short — ember or log falling out could ignite flooring

- No CO detector installed — incomplete combustion can produce dangerous carbon monoxide levels

Conduct a first fire test at low heat for approximately 2 hours to cure the paint and sealants on the insert (this is normal — expect some smoke and odor from the curing process). Verify proper draft by observing that smoke goes UP the chimney flue and does not spill into the room. Check carbon monoxide levels in the room using a CO detector — levels should remain at 0 ppm during normal operation. Test the blower fan for proper operation and verify it distributes heat effectively. Check all joints and connections for any smoke leakage.

1. Open the insert damper fully and light a small fire with newspaper and kindling

2. Observe smoke flow — it should draw up into the chimney immediately

3. If smoke enters the room, check draft (may need to warm the flue first with newspaper)

4. Gradually increase fire size but keep heat moderate for the first 2 hours (curing period)

5. Expect some smoke and paint odor during initial curing — ventilate the room

6. Monitor CO detector throughout the test — must remain at 0 ppm

7. After the fire is established, turn on the blower fan and verify hot air circulates into the room

8. Check all visible joints (liner connection, surround edges) for any smoke leakage

9. Check the chimney top from outside — smoke should exit cleanly from the rain cap

- Smoke spills into room on first light — chimney is cold, pre-warm the flue by burning newspaper held in the firebox opening

- CO detector reads above 0 ppm — serious issue, extinguish fire and check liner connection and combustion air supply

- Blower fan does not activate — check electrical connection or verify the fan thermostat requires higher temperature

- Strong paint/chemical odor — normal during first burn curing, ventilate well and maintain low-medium heat