Flue relining
Sweep & inspection
Caps & crowns
Masonry repair
Gas fireplace serviceLevel 1 sweep and inspection to the NFPA 211 annual standard - flue, crown, cap, and flashing checked and photographed
Chimney sweep logs do not sweep chimneys. They loosen some creosote - which then falls where a brush and vacuum still have to collect it.
HeatShield Flue Liner Replacement: The San Antonio Owner’s Guide
If your HeatShield flue liner has failed, we stock and install replacement liner systems in San Antonio for an installed price that typically runs $2,800 to $4,600, and most swaps are finished in one visit. HeatShield’s ceramic coating can crack, separate from the flue wall, or show gaps at the joints, and once that happens the liner no longer protects your home the way it should. Homeowners usually find out after a Level 2 inspection flags it, after a chimney sweep pulls out flaking material during a cleaning, or after water stains show up on the ceiling near the chase.
Here’s the thing about the HeatShield name. HeatShield is a resurfacing product, not a rigid liner. When we say “HeatShield flue liner replacement” in San Antonio, what’s usually happening is one of two jobs: either we’re replacing the entire system because the HeatShield coating delaminated beyond repair, or we’re installing a new stainless liner (DuraFlex, typically) because the HeatShield application was never a good fit for that particular flue. We’ll walk you through which one actually applies to your chimney. No guesswork, no vague warnings. Just what we saw, what it costs, and what we recommend.
Ruben Castellano has looked at hundreds of HeatShield jobs across San Antonio, and the honest take is this: the product works well in the right flue, but it does not last forever, and Texas humidity plus our wild temperature swings do not do it any favors. More on that below.
Key Takeaways
- HeatShield liner replacement in San Antonio typically costs $2,800 – $4,600 installed.
- Most replacements we complete in one visit, with a written price before we start.
- If the HeatShield coating has failed, partial patching is sometimes possible, but full replacement is often the only safe option.
- Every replacement carries our written 365-Day Done Right Promise. If it fails within the first year, the second visit is free.
Which HeatShield Models This Applies To
HeatShield is not a single liner model; it’s a category of ceramic-based resurfacing applied to existing flue tiles. The system goes by a few application types depending on the chimney’s construction, but for San Antonio homeowners the practical question is simpler: does your chimney have a clay tile flue that was recoated with HeatShield, or does it have a full HeatShield system that now needs attention?
We run into three common scenarios. First, the original HeatShield application is going on 15 to 20 years old and the coating has started to separate in spots, especially near the top where San Antonio’s rain and summer heat hit hardest. Second, a chimney fire years ago damaged the underlying tile, and the HeatShield was applied as a band-aid rather than a permanent rebuild. Third, someone applied HeatShield to a flue that really needed a rigid liner instead, and the coating has cracked at the joints because the flue moves.
Here’s the compatibility gotcha most San Antonio homeowners never hear about: HeatShield resurfacing works best when the original flue tile is still structurally sound. If the tile has shifted or spalled, the coating cannot hold, and you will chase failures every few years. That’s when we recommend replacing the system with a DuraFlex stainless liner instead of another HeatShield application. We’re an independent service provider, by the way. Alcott Chimney San Antonio is not affiliated with HeatShield. We install and service their product, but our loyalty is to your chimney’s actual condition, not a brand name.
To identify what you have, check the paperwork from your original installation, or look for a metal tag on the chimney cap or in the firebox. If you cannot find either, we’ll identify it during the inspection. That takes about an hour, and the camera report is yours to keep.
Styles & brands we work with





Signs Your HeatShield Flue Liner Replacement Is Failing
- Flaking or sandy material in the firebox or at the cleanout door. This is the most common sign we see. HeatShield breaks down in stages, and the first stage looks like coarse sand or small ceramic chips collecting at the bottom of the flue. That material is the coating eroding from the flue wall.
- Water stains on the ceiling or walls near the chimney chase. When the HeatShield coating separates, the flue loses its seal, and water that used to run down the inside of a sealed flue now migrates through gaps into the masonry or framing. In San Antonio’s rainy spring and fall, this shows up within one season.
- A sudden draft or cold smell around the fireplace on humid days. Cracks in the coating create a pathway for outside air, and when the barometric pressure drops before a storm, your living room can smell like the inside of a chimney. That is not normal, and it is usually fixable.
- Visible cracks or hairline separations in the coating at the top of the flue. If you can see the top of your chimney from a ladder, look for white or gray coating that has pulled away from the tile like old paint. Do not climb onto the roof to look. A phone camera on a selfie stick works fine, or we can take a look.
- You have not had the flue inspected in more than five years, and the home is over 20 years old. This one is less a symptom and more a pattern. Most HeatShield installations in San Antonio date to the early-to-mid 2000s, which means many are now at or past their expected service life. If that is your timeline, an inspection is overdue.
If you see flaking material or water stains, do not use the fireplace until we have looked at it. A compromised flue liner is a chimney fire and carbon monoxide risk, plain and simple. That is not a scare tactic. It is the same thing we tell our own families.
Replacement Cost & What’s Included
For a standard single-flue HeatShield replacement in San Antonio, expect to pay between $2,800 and $4,600 installed. That range covers the parts, the labor to remove the failed coating where needed, the new liner system, and the connection to your appliance or fireplace. A two-story chimney that needs scaffolding or a steep-pitch roof adds cost, as does a chimney that needs masonry repair before the liner can be installed. A straightforward one-story ranch in Alamo Heights typically lands at the lower end. An older limestone home with a tall chimney and hidden chase damage lands higher.
- Parts: $900 – $1,600 depending on flue size and liner grade
- Labor and installation: $1,500 – $2,400
- Masonry repairs (if needed): $400 – $1,100
- Camera inspection with photo report: Included, never an add-on
Every HeatShield flue liner replacement we do in San Antonio comes with a written price before any work begins. That price is the price. No surprise line items at the end, no “while we were in there” phone calls. The work also carries our written 365-Day Done Right Promise: if the repair fails within a year, we come back and make it right at no charge for the second visit. That is not a sales pitch. It is in writing on every job.
See the difference
Before
After
Before
After
Before
AfterDIY or Call Us?
There is no safe DIY version of a flue liner replacement. This is not like caulking a window or patching drywall. The liner sits inside the flue, often 20 to 30 feet down, and installing one requires working at height, running tools through a narrow chase, and making connections that must hold up to flue gases and 1,500-degree temperatures. A mistake here does not leak onto the floor. It leaks into the house, or it fails during a fire.
What you can safely do is inspect from the ground. Look for flaking in the firebox, check for water stains on the ceiling, and take a photo of the chimney cap from the driveway with your phone. That gives us a head start. Beyond that, give us a call at (903) 515-5079 and we’ll bring the ladder, the camera, and the liner. Estimates are free, and you’ll get a written price before you commit to anything.
FAQs
In the San Antonio climate, a HeatShield application typically lasts 15 to 20 years when the original flue tile was sound. The combination of summer heat, spring and fall humidity, and wide temperature swings shortens the service life compared to drier climates. If the coating was applied over already-damaged tile, it can fail within five years or less. Call (903) 515-5079 to have us camera-inspect yours and give you an honest read on what is left.
Sometimes, yes, but only when the separation is small, isolated to one joint, and the underlying tile is intact. If the coating has delaminated across multiple sections, patching buys you a year or two at most and often costs half as much as a full replacement. We will show you the camera footage and let you decide with real numbers in hand. For any doubt, we recommend the replacement.
Most single-flue HeatShield replacements in San Antonio take four to six hours on site, and we complete the job in one visit. If masonry repairs are needed before the liner goes in, that adds a second day for the mortar work to cure. We’ll tell you at the estimate stage which one applies. You will also know the technician’s name and see their photo before we arrive, and they’ll show a photo ID badge at the door.
Yes. Our trucks commonly carry DuraFlex and HeatShield components in the sizes most San Antonio chimneys use, along with Gelco and Copperfield parts for related repairs. If your flue needs a size we do not have on board, we can usually have it within a day or two. The estimate tells you which is which before we climb a ladder.
Call for a Free Estimate
If your HeatShield liner is showing cracks, flaking, or water leaks around the chimney, call Alcott Chimney San Antonio at (903) 515-5079. You’ll speak with a live person, you’ll get a straight answer from Ruben Castellano or one of his technicians, and you’ll receive a written price before any work starts. We serve San Antonio and the surrounding areas, and we will tell you exactly what we found, what it costs, and whether the work can wait. As Ruben puts it: “I would rather give you a straight answer today than a vague promise you have to call us back about tomorrow.”
Written by Ruben Castellano, Owner, Alcott Chimney San Antonio at Alcott Chimney San Antonio, serving San Antonio and nearby areas.