Masonry repair
Sweep & inspection
Caps & crowns
Flue relining
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.
Fast, Reliable Gas Fireplace Repair Across San Dimas
Gas fireplace repair in San Dimas typically runs $185 – $480 for most service calls, with common fixes like thermocouple replacement, pilot assembly cleaning, and gas valve diagnostics usually falling in the $210 – $320 range. Most repairs in San Dimas are done same-day or next-day, depending on parts availability. If your gas fireplace won’t light, keeps shutting off, or smells odd when running, call (661) 402-9036 and we’ll get a technician out to your San Dimas home fast.
We know San Dimas homes. The mix of 1960s-1980s ranch houses near Bonita Avenue and newer foothill properties along San Dimas Canyon Road means we see both aging masonry fireplaces and modern direct-vent gas units. Each has its own failure patterns. Our Gas Fireplace Repair team works on both, and we stock parts for the brands most common in this area.
Why Hadley Chimney West Covina Is San Dimas’s Preferred Gas Fireplace Repair Company
Hadley Chimney Sweep was founded in 2003, and Cory Mitchell still oversees every job we book. Homeowners in San Dimas call us because we answer the phone with a live person 24/7, give a written price before any work starts, and send background-checked, uniformed technicians who arrive in a tracked window, not a four-hour guess.
Every gas fireplace repair in San Dimas comes with our 365-Day Done Right Promise: a written guarantee on every repair, and a free second visit if the repair fails. No fine print, no upsell. We also document everything with before-and-after photos and a digital invoice you can pay from your phone. That’s the Relay Visibility Guarantee, and it’s standard on every job we do in San Dimas.
Dispatch for San Dimas is coordinated from our Los Angeles office, but crews live and work locally. That means we know the streets, the housing stock, and the specific chimney problems this city throws at us.
Styles & brands we work with
Our Gas Fireplace Repair Services in San Dimas
DuraFlex Flue Liner Installation
Older San Dimas homes, especially the ranch-style builds from the 1960s through 1980s, often have original terra cotta flue liners. These crack under thermal stress from repeated heating and cooling cycles. When that happens, your gas fireplace vents carbon monoxide into the wall cavity instead of up and out. We install DuraFlex stainless steel liners that slide directly inside the old flue, sealing off those cracks permanently. It’s the same liner system chimney pros across the country rely on.
HeatShield Smoke Chamber Repair
The smoke chamber is the funnel-shaped section above your firebox that directs exhaust into the flue. In San Dimas homes with original masonry, this area often has gaps and deteriorated mortar. HeatShield is a ceramic repair compound we apply to rebuild and seal the smoke chamber. It’s rated for gas fireplace use and eliminates the gaps where embers and exhaust can migrate into the home’s framing.
Thermocouple and Pilot Assembly Service
If your gas fireplace in San Dimas lights but won’t stay lit, the thermocouple is usually the culprit. This small sensor detects heat from the pilot flame and tells the gas valve to keep supplying fuel. When it fails, the valve shuts off. We replace thermocouples and clean or rebuild pilot assemblies on all major brands. Typical cost in San Dimas: $210 – $280, parts included.
Gas Valve Diagnostics and Replacement
Gas valves control the flow of fuel to your fireplace. When one fails, you’ll either get no flame or a weak, sputtering one. We diagnose valve issues with a manometer (a pressure gauge that tells us exactly what the gas line is doing) and replace faulty valves with manufacturer-approved parts. In San Dimas, valve replacement typically runs $380 – $520 depending on the unit.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in San Dimas
Hadley works with materials from brands chimney professionals actually use: HeatShield ceramic repair compound, Gelco sealants, Olympia Chimney components, and Famco venting products. We don’t put whatever’s cheapest on the truck. When we install a repair part in a San Dimas home, it’s a part built to handle years of damp foothill winters and Santa Ana heat swings. That matters here more than most places.
Common Gas Fireplace Repair Problems We See in San Dimas Homes
- Third-degree creosote tar glaze in older masonry fireplaces. Damp winter air from the San Gabriel foothills seeps into flues and mixes with combustion byproducts, forming a hard, shiny tar. Brushing won’t remove it. We use chemical treatments to break it down, then remove it safely.
- Spalling bricks from Santa Ana winds. When hot, dry Santa Anas hit exterior masonry that’s been saturated by winter rain, the rapid drying causes the brick face to pop off. Those brick fragments can fall and lodge against your damper, jamming it open or shut.
- Pilot outages from cold air inversion. Foothill homes with unlined masonry chases around the gas flue pipe can draw cold air down during winter temperature inversions. Cold air drops onto the pilot assembly, snuffing the flame and causing rollout into the firebox.
- Carbon monoxide from cracked terra cotta liners. North of Bonita Avenue, many original flue liners have cracked under decades of thermal cycling. We regularly find hairline fractures running several feet up the flue that are invisible from the outside but show up clearly on camera inspection.
See the difference
Before
After
Before
After
Before
AfterPricing for Gas Fireplace Repair in San Dimas, CA
A typical gas fireplace repair in San Dimas runs $185 – $480. Here’s what you can expect:
- Service call and diagnostic: $85 – $120 (waived if we do the repair)
- Thermocouple replacement: $210 – $280
- Pilot assembly cleaning or rebuild: $195 – $290
- Gas valve replacement: $380 – $520
- DuraFlex flue liner installation: $1,400 – $2,800 (depends on flue length and access)
- HeatShield smoke chamber repair: $650 – $1,100
Nothing gets added at the door. You get a written price before we pick up a tool. Call (661) 402-9036 for an exact quote. Estimates are free.
We Also Serve Cities Near San Dimas
Hadley Chimney West Covina handles gas fireplace repair throughout the eastern San Gabriel Valley. If you’re in Gas Fireplace Repair in San Dimas and have neighbors in La Verne, Glendora, Covina, or Azusa who need the same service, we’re already out there regularly. Same pricing, same written guarantee, same tracked arrival window.
Serving San Dimas, CA - Our Local Coverage Area
We’re based in the San Dimas area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs – Gas Fireplace Repair in San Dimas
Yes. Moisture from damp foothill air condenses inside the flue and mixes with combustion byproducts, forming a sticky, tar-like creosote that bonds to the flue walls. In gas fireplaces, this buildup is typically lighter than wood-burning fireplaces, but it still reduces draft and can create an odor when the unit runs. In San Dimas homes with older masonry chimneys, the problem is worse because cracked terra cotta liners let moisture in from all sides. We recommend an annual inspection, especially if your gas fireplace uses a masonry flue. Call (661) 402-9036 to schedule one.
A liner is not about wood. Gas combustion produces carbon monoxide and acidic water vapor. Without a proper liner, that water vapor condenses inside the masonry and dissolves the mortar from the inside out. The result is a flue that leaks exhaust into your wall cavities. In San Dimas, homes built before the 1990s often have unlined masonry flues or original terra cotta liners that have cracked. A DuraFlex stainless liner seals the flue and routes exhaust up and out. If your gas fireplace is vented through an old masonry chimney, a liner is not optional. It’s the difference between a safe system and a slow carbon monoxide leak.
Annually, even if you only use it a few times each winter. Gas fireplaces in foothill areas face a few things flatland homes don’t: Santa Ana winds that dry and crack exterior masonry, damp winter air that seeps into flues, and temperature swings that stress terra cotta liners. A quick inspection catches cracks, pilot issues, and vent blockages before they become safety problems. Cory Mitchell recommends an annual Level 1 inspection for any gas fireplace in San Dimas. Call (661) 402-9036 and we’ll get you on the schedule.
Yes. Santa Ana winds hit San Dimas hard, especially in foothill neighborhoods near San Dimas Canyon. The wind itself doesn’t do the damage; the rapid drying does. Masonry that’s been saturated by winter rain dries too fast in hot, dry Santa Ana conditions, causing the surface to spall, or flake away. Chimney crowns, which are just mortar poured over the top of the chimney, crack and let water into the structure. Flashing around the roofline can also pull loose. We inspect crowns and flashing as part of our Chimney Repair in San Dimas. If yours is cracking, we’ll show you photos and give you a written price before any repair work starts.
A Level 1 inspection is a visual check of the fireplace, firebox, and accessible portions of the flue. It’s appropriate when your system hasn’t changed since the last inspection. A Level 2 inspection adds camera scanning of the entire flue interior and is required when you’re buying or selling a home, after a chimney fire, or if the system has been modified. In San Dimas, we recommend Level 2 for any home with an original terra cotta liner, because those liners crack in ways you can’t see from the roof or the firebox. The camera finds the cracks. Call (661) 402-9036 to book either level of inspection.
What Happens When You Book a Gas Fireplace Repair in San Dimas
You call, a live person answers, and we schedule a tracked arrival window. The technician shows up in uniform, introduces himself, and walks you through what he’s checking. If we find a problem, you see photos. You get a written price. You approve it before any work begins. When the repair is done, you get before-and-after photos and a digital invoice you can pay from your phone. Every repair comes with the 365-Day Done Right Promise in writing.
Call (661) 402-9036 for a free estimate on gas fireplace repair in San Dimas. We answer the phone. We show up. We show you the proof.
Written by Cory Mitchell, Owner at Hadley Chimney West Covina, serving San Dimas and the eastern San Gabriel Valley since 2003.