Last updated: April 23, 2026
Furnace repair in San Diego County typically runs $200 to $900, starting with an $89 diagnostic that gets credited toward the fix. Ignitor and flame sensor problems make up most of the cheap end. A cracked heat exchanger is the one repair that usually means it's time to talk about replacement instead.
The tract blocks around Sandrock Road and the streets above Aero Drive run original 1950s-60s systems now failing, and duct leakage testing on replacements routinely catches degraded insulation and rodent damage. Sitting on a central mesa well inland of the coast, Serra Mesa carries a full summer cooling load, and right-sizing the replacement is the recurring fix for oversized originals.
The signature job is a heat-pump conversion paired with ductwork renewal. Original attic or subfloor ducts are fifty-plus years old with degraded insulation, failed seals, and rodent damage on a large share of homes. Manual J load calcs almost always show the original equipment was oversized, so replacements typically downsize tonnage while improving comfort.
A furnace repair under roughly $500 on a unit less than 12 years old is almost always the right call. A cracked heat exchanger is different. It's a safety issue, not just a repair line item, because a cracked exchanger can leak combustion gases into the home. On a furnace old enough to need one, we usually recommend replacement over repair, and we explain exactly why before you spend money either way.
The $89 diagnostic gets credited toward the repair once you approve it. SDG&E and TECH Clean California rebates apply to new equipment, not repairs, so they come into play only if a repair turns into a replacement conversation, most often after a heat exchanger fails. We offer financing for larger repairs, and we'll tell you plainly when a repair isn't worth it anymore.
Most Serra Mesa homes land in the $200 to $900 range. Heat-pump conversions with ductwork renewal are the signature job, with original attic ducts long past service life across most of the tract., which is the main thing that moves the number here.
Central San Diego furnaces are often original equipment in older homes, so the repair-vs-replace line gets crossed more often here. When a repair still makes sense, ignition failures and cracked flame sensors are the usual ticket, priced at the county standard.
$200 to $900 covers most repairs, including the $89 diagnostic that gets credited toward the fix. Ignitor and flame sensor issues run under $500. A gas valve, control board, or blower motor runs $400 to $900.
Usually yes if the repair is under $500 and the furnace is less than 12 years old. A cracked heat exchanger is the exception. That's a safety issue, and on an older furnace we typically recommend replacement instead.
A flame sensor cleaning or replacement is usually the least expensive fix, typically $150 to $350, and it's one of the most common reasons a furnace shuts off right after lighting.
A heat exchanger replacement runs $1,500 to $3,500 and is the most expensive single repair. Because of the safety issue involved and the age of furnaces that usually need one, we walk through the full replacement cost alongside it.
No trip fee, no surprise line items. We confirm the price before any work starts.