In Crown Heights, most boiler chimney problems end at the same solution: a new stainless-steel liner. The six-story pre-war buildings along Eastern Parkway, the walk-up apartment houses on Nostrand and Kingston Avenues, the brownstone rows on President and Carroll Streets — their boilers were replaced and converted over the decades while their chimneys stayed clay. Oil-to-gas conversions are the reason so many of these flues are failing now: cooler gas exhaust condenses inside a clay flue sized for an old oil burner, and the condensate dissolves mortar and cracks terra cotta tiles from the inside, year after year. When the camera finds a liner that is cracked, missing in sections, or too deteriorated to trust, relining is the fix — and it is the fix that protects both the boiler and the building. Sweeps Chimney Services installs stainless-steel chimney liners across Crown Heights with 25 years of experience, sized to the connected boiler and built for the exhaust chemistry of modern gas heat. Call (347) 297-9646 or message us on WhatsApp — we answer 24/7, calmly and without pressure.
A liner does three jobs at once. First, it gives exhaust a smooth, correctly sized passage — which is what fixes draft. An oversized clay flue runs cool and drafts weakly; a stainless liner sized to the boiler keeps exhaust velocity up, so gases leave instead of condensing. Second, it contains the exhaust. Cracked clay tiles let flue gases — including carbon monoxide — seep into the masonry and from there into the building. A continuous stainless liner is a sealed conduit from the boiler to the roof. Third, it survives the chemistry. Stainless steel resists the acidic condensate that destroys clay and mortar, which is exactly why it is the standard answer for gas-converted flues.
Sizing is the engineering heart of the job, and it is where Crown Heights buildings most often went wrong in the past. A liner is not one-size-fits-all: it is matched to the boiler’s input and the flue’s height and configuration, so draft is correct from the first firing. Too large and you repeat the condensation problem; too small and you strangle the boiler. We measure the flue interior with the camera, document the connected boiler’s requirements, and size the liner to the pair — not to a guess, not to what fits on the truck.
Installation is less disruptive than most owners expect. The liner is dropped from the roof down through the existing flue — the old clay tiles stay in place around it — then connected to the boiler at the bottom and terminated with a proper cap at the top. No walls opened, no masonry torn out. Most residential boiler liner installs complete in a day; larger apartment-building stacks take longer and are scheduled with the super or managing agent so heat interruption is planned, not improvised. The boiler is down during the work and restarted and draft-checked when the liner is in.
There is one more reason Crown Heights buildings reline now rather than later: the pre-new-boiler moment. If a new boiler is going in, the chimney should be camera-inspected first, and if the liner is compromised, the new liner goes in with the new boiler. A new boiler connected to a failing clay flue inherits every problem the old boiler had — weak draft, condensation, spillage risk — and a venting defect that predated the installation can void the equipment warranty. Lining the flue before the boiler fires for the first time is the most cost-effective protection the installation can have.
Carbon monoxide safety: A cracked liner is a CO pathway — exhaust seeps through broken tiles into the building instead of rising out the top. If your CO alarm sounds, or anyone in the building has headaches, dizziness or nausea — get everyone out of the building, call 911, and do not go back inside until emergency responders say it is safe.
Before installing a new boiler in Crown Heights
Camera-inspect the chimney before the boiler is ordered. If the clay liner is cracked, spalling, or missing sections — the usual findings after an oil-to-gas conversion — the stainless liner is sized and installed as part of the boiler project, so the new unit drafts correctly from day one and the warranty is protected.
Pricing
Stainless-steel chimney liner installation starts at $3,000 in Brooklyn, including labor and materials. The inspection that determines whether you need one follows Level 2 pricing: starts at $199.
Frequently Asked Questions
What size liner does my boiler need?
It depends on the boiler’s input rating and the flue’s height and layout — there is no standard size. We measure the flue interior with the camera and match the liner diameter to what the connected boiler requires for proper draft. Correct sizing is the difference between a liner that fixes the problem and one that repeats it.
Does the old clay liner get removed during installation?
Usually not. The stainless liner drops inside the existing flue, with the old clay tiles remaining in place around it. Removal is only necessary if the flue is too damaged or too narrow for the liner to pass — the camera inspection determines that before any work is quoted.
What is the difference between rigid and flexible liners?
Rigid liners are straight stainless sections for straight flues; flexible liners navigate offsets and bends. Most boiler flues in pre-war buildings have at least a slight offset where the connector enters, so flexible stainless is the common choice — it forms one continuous sealed run from boiler to roof.
Will relining fix my boiler's draft problems?
If the draft problem comes from the flue — oversized clay passage, damaged liner, rough deteriorated walls — then yes: a correctly sized smooth liner restores proper exhaust velocity and draft. If the problem is a blockage or a boiler-side issue, the camera inspection identifies that first so you do not pay for a liner you do not need.
How long does a liner installation take?
Most residential boiler flues are done in a day: liner dropped from the roof, connected at the boiler, capped and draft-tested. Larger apartment-building stacks can run longer, and we schedule those with building management so the heat interruption is planned around the building’s needs.
Call (347) 297-9646 or message us on WhatsApp — we answer 24/7, calmly and without pressure. Heating season is here — slots fill fast, book before the rush.
Sweeps Chimney Services INC, 68 Jay Street, Brooklyn, NY 11201, (347) 297-9646.
Related: Crown Heights chimney services | Boiler Chimney Inspection Crown Heights | Boiler Chimney Inspection | Chimney Liner Installation Bedford Stuyvesant