Every furnace call starts with a combustion and carbon monoxide safety check, not just a symptom fix.
Heat exchanger cracks, ignitor failures, and gas valve issues all fall within our scope.
If you're dealing with a pilot light that won't stay lit, an ignitor that clicks but never catches, or a furnace that runs but blows cold air, you already know furnace failures carry a safety dimension — carbon monoxide and gas leaks — that most other HVAC repairs don't, so the diagnostic has to start there.

Waiting rarely saves money and often turns a same-day repair into a longer, more involved job.
AAA Pro HVAC built its furnace repair process around one idea: diagnose first, quote honestly, fix it right.
Every truck across San Bruno, CA carries the tools and common parts specific to furnace repair, so most calls finish in a single visit.

Cracked heat exchangers get flagged immediately as a safety issue, not just a repair line item.
We carry manufacturer service manuals for major furnace brands.
Diagnosis happens first, and the quoted flat rate reflects the actual confirmed fault.
We understand a dead furnace in winter is a pipe-freezing risk, not just a comfort issue.
Every job starts with a real diagnosis, not a guess — here's the full scope of what our furnace repair technicians handle across San Bruno, CA.
Hot surface ignitors crack over time and simply stop glowing — we test resistance rather than replacing on assumption. Techs handling ignitor & pilot light repair carry the specific parts and tools this job calls for, not a generic kit.
A gas valve that won't open or won't seal is tested with proper manometer readings, not just listened to. Techs handling gas valve diagnostics carry the specific parts and tools this job calls for, not a generic kit.
We use a combustion analyzer and visual borescope inspection, not guesswork. Techs handling heat exchanger inspection & repair carry the specific parts and tools this job calls for, not a generic kit.
We test motor amp draw against rated spec before replacement. This is one of the most requested furnace repair calls we get across San Bruno, CA.
Blocked or improperly sloped venting can back-draft combustion gases into the home. This is one of the most requested furnace repair calls we get across San Bruno, CA.
A furnace that won't respond to the thermostat at all sometimes traces to a control board fault rather than the burner assembly. Techs handling thermostat & control board diagnostics carry the specific parts and tools this job calls for, not a generic kit.

Gas odor reports get immediate safety instructions before dispatch details.
Techs arrive with combustion analyzers and common ignitor/gas valve stock loaded.
Flat-rate quote follows the confirmed fault, before repair begins.
Heat exchanger findings are documented clearly regardless of outcome.

Tech tested the ignitor's resistance right in front of me and swapped it in under thirty minutes.
Turned out to be a failed gas valve — they caught it with a proper pressure test, not a guess.
Shut the furnace down immediately for safety and walked me through the options.
Pilot light kept going out every few hours.

Usually a failing ignitor or a fouled flame sensor — both are testable with the right equipment rather than replaced blind.
We'll walk you through options including repair versus replacement honestly.
Could be a delayed ignition fault, a failed gas valve, or a limit switch issue — a full diagnostic narrows it down.
Electric resistance furnaces fail differently than gas units, and we diagnose accordingly.
Immediately — leave the area and call, don't attempt to diagnose it yourself.
Call dispatch for a live arrival estimate based on current demand.

Our furnace repair crews are positioned throughout San Bruno, CA to keep response times realistic, not just promised.
☎ Call +1-866-805-8548 for San Bruno Service