San Antonio · Furnace Ignitor Replacement Repair · Family-Owned Since 1996
The hot surface ignitor (HSI) glows like a toaster element to light your gas. They last 5–7 years and fail predictably — when yours dies, the gas valve won't open and you get a click but no fire.
Typical price
$249–$385
Time to fix
45–75 minutes
Urgency
High in winter — no heat
Modern gas furnaces use a hot surface ignitor (HSI) — a thin silicon carbide element that heats to 2,000°F+ to light the gas. When you hear the click and then nothing happens, the HSI either isn't heating or has cracked completely.
HSIs are fragile and have a predictable lifespan of 5–7 years. They're also the most common no-heat call in San Antonio every November when furnaces fire up for the first cold snap. The good news: they're cheap to replace and almost always same-day.
Replacement runs $249 to $385. The part itself is $45–$120 depending on furnace brand. We always check the flame sensor and limit switch at the same visit — they fail in pairs surprisingly often.
What it costs in San Antonio
$249–$385 — Includes new ignitor, flame sensor cleaning, and full ignition sequence test. Our $59 diagnostic is waived when you approve the repair, so you only pay for the fix itself.
If two or more of these sound familiar, it's probably your furnace ignitor replacement.
Here's exactly what a Carnes and Sons tech does at your house — no mystery, no upselling.
Set thermostat to call for heat. Watch through the inspection port: inducer runs (good), gas valve opens, ignitor should glow orange-white. If no glow, ignitor is dead.
Disconnect the ignitor and measure resistance. Healthy ignitors read 40–90 ohms (varies by brand). Open circuit or way off range means failed.
Visual inspection — even a hairline crack means the ignitor is shot. Also check the wire connectors for corrosion (common in attic furnaces).
Match the exact OEM ignitor (universal Norton 271N works for most brands). Install without touching the element. Run through 3 full ignition cycles to confirm reliable lighting.
Get Your Furnace Ignitor Replacement Diagnosed Today
Tell us what's happening. We'll text you back in minutes — no call center, no robo-calls.
$249–$385 installed. The part is cheap ($45–$120), most of the cost is the diagnostic visit and labor — and we usually check/clean the flame sensor at the same visit so you don't have a repeat call in a month.
It's possible, but: handling the element with bare fingers ruins it instantly (skin oil), getting the wrong model number is common, and you're working inside a gas appliance. For $249–$385 done right with a warranty, most folks shouldn't DIY this.
5–7 years on average in San Antonio. Furnaces that run more (older or poorly insulated homes) burn through them faster. Annual maintenance with flame sensor cleaning helps.
Pilot lights are an always-on small flame from older furnaces (pre-1990s). HSI is electric, only fires when needed, much safer and more efficient. Almost every San Antonio furnace built since 1995 uses an HSI.
Not for another 5–7 years with normal use. We install OEM-grade or Norton 271N universal ignitors that are rated longer than the cheap aftermarket parts.
Absolutely — that's why November/December calls spike. Furnaces that ran fine all summer for the blower suddenly need to actually fire, and weak ignitors choose that moment to give up.
Other no-heat causes: bad flame sensor (we always check), failed pressure switch, gas valve issue, control board, or rolled-out flame triggering the safety. Our diagnostic identifies the actual fault — we don't just throw parts at it.
Yes — we keep same-day slots open in cold weather. Text (210) 600-5091 and we'll give you a real arrival window.
We're based in Stone Oak and roll trucks across San Antonio and the surrounding Hill Country every day.
License TACLB29435E · Family-Owned Since 1996
Cities & neighborhoods we serve
San Antonio · Stone Oak · Alamo Heights · Hollywood Park · Hill Country Village · Shavano Park · Castle Hills · Leon Valley · Helotes · Boerne · Fair Oaks Ranch · Bulverde · Timberwood Park · Garden Ridge · Schertz · Cibolo · Selma · Universal City · Live Oak · Converse · Windcrest · New Braunfels
No call center. The owner or one of his sons picks up.
(210) 600-5091