San Antonio · Gas Valve Replacement Repair · Family-Owned Since 1996
The gas valve opens and closes the fuel supply to your burner on command from the control board. When it fails, no amount of new ignitors will help — the gas just isn't getting there.
Typical price
$489–$789
Time to fix
90 minutes to 2 hours
Urgency
Critical — no heat, possible gas safety issue
The gas valve is a solenoid-controlled valve that lets fuel into your burner when the control board calls for heat. It's the only thing between your gas line and the burner manifold. When it dies, the burner can't fire — even if the ignitor is glowing and the flame sensor is perfect.
Common failures: solenoid coil burns out (board sends signal, valve doesn't open), valve sticks open (dangerous — gas continues flowing after burner shuts off, usually caught by safeties), or modulating valves with electronic control fail intermittently.
Replacement is $489–$789 — the part is $150–$350 depending on furnace brand and whether it's a single-stage, two-stage, or modulating valve. Plus labor to safely shut off gas, swap the valve, leak-test all joints with soap solution, and verify proper manifold pressure with a manometer.
What it costs in San Antonio
$489–$789 — Includes new gas valve, leak-test, manifold pressure verification, and full ignition 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 gas valve replacement.
Here's exactly what a Carnes and Sons tech does at your house — no mystery, no upselling.
If board is sending 24V but valve doesn't open, valve is bad. If no signal, problem is upstream (board, wiring, pressure switch).
Confirm the gas company is delivering proper pressure (7" WC for natural gas). Low pressure makes valves appear bad when they're not.
Shut off gas at the supply, drain the line, swap valve with thread sealant rated for gas, leak-test every joint with soap solution under pressure.
With burners running, set manifold pressure to manufacturer spec with the regulator. Check flame appearance — should be blue with no yellow tipping. Document everything.
Get Your Gas Valve Replacement Diagnosed Today
Tell us what's happening. We'll text you back in minutes — no call center, no robo-calls.
$489–$789 installed in San Antonio. Single-stage valves are cheapest, two-stage and modulating valves are more expensive parts. Always includes leak-testing every joint with soap solution and verifying manifold pressure.
Absolutely not — this is gas work that requires licensed technicians in Texas. Improper installation causes gas leaks, explosions, and CO poisoning. Even DIY-friendly homeowners should leave this one alone.
It can be. A valve stuck open lets unburned gas into your home — usually caught by the limit switch or pressure switch safety, but not always. If you smell gas, shut off the gas supply at the meter and call us (or 911 for serious leaks).
15–25 years on average. They're robust components. When they fail it's usually age or surge damage.
Sometimes — gas valves are typically covered for 5–10 years under parts warranty. We always check warranty status before quoting and pass through any covered parts cost.
We'll quote both the repair and a replacement so you can decide. On a 20+ year-old furnace, a $700 gas valve might not make sense if other components are also tired. We'll give you the honest math.
Usually age. Sometimes a power surge took out the solenoid. Occasionally contamination in the gas line. We'll inspect to identify the cause and recommend a surge protector if that was the trigger.
Yes, especially in cold weather. We keep same-day slots open. Text (210) 600-5091 for 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