Fireplace Inserts and Liner Installation

Regulated hardware

An insert is regulated hardware, the fireplace around it is not

This is the distinction almost nobody draws. EPA states it did not include new indoor fireplaces for regulation, based on its review of data indicating that typical fireplaces are not effective heaters, and put them into a voluntary program covering cleaner-burning new fireplaces and retrofits¹. A wood-burning insert is a different animal. It is a wood heater, and wood heaters carry a mandatory certification with a number attached.

The number is in the regulation. Affected wood heaters manufactured, imported or sold at retail on or after 15 May 2015 had to be certified to a weighted average of 4.5 g/hr, and from 15 May 2020 the limit is 2.0 g/hr². A cord wood alternative sits at a weighted average of 2.5 g/hr and requires a cord wood test method approved by the Administrator². EPA published its amendments on 2 April 2020 and kept 15 May 2020 as the retailer sell-through date³.

Then there is the chimney. CSIA recommends a Level 2 inspection if you are planning on lining or relining the chimney, and also when a new appliance is added or an existing one is replaced with a dissimilar one⁴. An insert is both of those at once. A Level 2 requires video scanning of the chimney interior, a trip onto the roof, and inspection within accessible attics, basements and crawl spaces⁴.

Six things that separate an insert job from a fireplace job

The regulation, the dates and the inspection level change once an appliance goes in.

A wood insert is a wood heater

EPA's rule reaches wood heaters, not fireplaces. It does not affect existing woodstoves already in use, does not apply to heaters fueled solely by oil, gas or coal, and does not reach outdoor fireplaces, fire pits, pizza ovens or chimineas¹. A certified appliance inside an unregulated firebox is the point.

The limits, in grams per hour

A weighted average of 4.5 g/hr applied from 15 May 2015, and 2.0 g/hr from 15 May 2020². The cord wood alternative compliance option sits at 2.5 g/hr and requires a cord wood test method approved by the Administrator². Ask which of those a quoted model was certified against.

Crib wood and cord wood are not the same test

The subpart distinguishes crib wood testing under EPA Method 28R from an alternative cord wood test method approved by the Administrator². EPA says the 2015 rule is based on tests that burn standardized configurations of lumber rather than logs, the wood a homeowner would actually burn³.

Relining triggers a Level 2

CSIA names lining or relining as a Level 2 situation, alongside adding a new appliance and replacing one with a dissimilar appliance⁴. Video scanning of the interior is required at Level 2, and where size or multiple offsets prevent it, the sweep must note that in the report⁴.

Flue sizing has published ratios

CSIA sets out NFPA 211 guidelines for flue sizing: one twelfth of the fireplace opening area for round flues, one tenth for square or standard rectangular flues, and one eighth for rectangular flues with an aspect ratio of 2 to 1 or greater⁴. Ask your installer to show the arithmetic.

A freestanding stove has its own figures

If a stove goes on the hearth rather than an insert into the firebox, CSIA says clearances for unlisted appliances should conform to local code, normally 36 inches from appliance to combustible material in all directions⁵. Floor protection should extend 18 inches beyond the stove unless listed otherwise⁵.

Wood heater limit since 15 May 20202.0 g/hr weighted average

Published installed priceNone, for liner or insert

What does an insert or a liner cost?

No authoritative source publishes an installed price for a stainless liner, a cast-in-place liner or a wood, gas or pellet insert. EPA regulates emissions, not prices. CSIA publishes procedures, not rates. The May 2025 national occupational employment and wage table contains no occupation with the word chimney or sweep, so there is no federal wage to work back from⁸. Any average cost range you have seen was not built on data like this.

What moves the number is scope, most of it knowable in advance. Relining pulls you into a Level 2 with a camera and a roof visit rather than a Level 1⁴. Flue shape and size decide the liner, and the sizing ratios are published⁴. The appliance is a list-price item you can check: EPA runs a compliance monitoring program and links a certified wood heater database⁶, though that database returned no readable model list to us, so no count is quoted here.

The emission limits come from the regulation and EPA's pages. No source here publishes an installed price, a labour rate or a liner price, so none is stated.

Hiring

How to hire for an insert or a reline

1

Who does the work

Usually one company sells the appliance, lines the chimney and inspects it, which is efficient and worth a second opinion. A CSIA Certified Chimney Sweep earns the credential by completing a review and passing the exam⁹, and CSIA tells homeowners to ask for the inspection by name and find someone else if the sweep does not recognise the term⁷.

2

What pros will ask

Which fuel: wood, gas or pellet. The dimensions and shape of the existing flue, since round, square and high aspect ratio rectangles carry different sizing ratios⁴. Whether the chimney has been lined before. Whether there has been a chimney fire, storm or seismic event, each its own Level 2 trigger⁴. The model number you are considering.

3

What to check before signing

That a Level 2 with video scanning is written into the scope, not offered as an extra⁴. That the report will say so if the interior could not be scanned⁴. That the certified model is named so you can check it against EPA's database⁶. And that any grams per hour figure comes with its test method, given EPA's note about lumber versus logs³.

Insert and liner questions, answered straight

Does my new wood insert have to be EPA certified?

If it is an affected wood heater, yes. Wood heaters manufactured, imported or sold at retail on or after 15 May 2015 had to be certified to a weighted average of 4.5 g/hr, and from 15 May 2020 the limit is 2.0 g/hr². A cord wood alternative compliance option sits at 2.5 g/hr². The rule does not affect existing woodstoves already in use in people's homes, so an old appliance staying put is not caught¹.

Why does my stove not behave like its certified rating?

EPA has said so itself. Its 2020 amendments page states that the 2015 rule is based on tests that burn standardized configurations of lumber, rather than tests that burn logs, the type of wood a typical homeowner would burn for heat³. The subpart distinguishes crib wood testing under EPA Method 28R from an alternative cord wood test method approved by the Administrator². A certified grams per hour figure is a laboratory result under a named method.

Do I need an inspection before the chimney is relined?

CSIA recommends a Level 2 when you are planning on lining or relining the chimney⁴. That is not a formality. A Level 2 requires video scanning of the chimney interior, and if scanning is impossible because of size or multiple offsets the sweep is told to note that in the report⁴. It also requires going on the roof and inspecting within accessible attics, basements and crawl spaces, and should cover all flues and their connected appliances⁴.

How is the right liner size worked out?

For fireplace flues, CSIA publishes the NFPA 211 guidelines as ratios of the fireplace opening area: one twelfth for round flues, one tenth for square or standard rectangular flues, and one eighth for rectangular flues with an aspect ratio of 2 to 1 or greater⁴. Ask to see the opening area measured and the ratio applied. Those figures reach you through CSIA citing NFPA 211, whose clause text was not read for this guide.

Could I put a freestanding stove on the hearth instead?

Different job, different figures. CSIA says clearances for unlisted appliances should conform to local code requirements, normally 36 inches from appliance to combustible material in all directions, and that floor protection should extend 18 inches beyond the stove unless listed otherwise⁵. The chimney obligations remain: the annual language CSIA quotes covers chimneys, fireplaces and vents once a year for soundness, freedom from deposits and correct clearances⁷.

Sources

Where these facts came from

Every figure on this page was read out of the page linked below. We do not cite cost aggregators.

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