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.
Bonita is unincorporated, so permits route through the County of San Diego. Bonita Country Estates and the equestrian-property residential along the Sweetwater River valley run larger 1970s-90s estate homes now hitting their replacement window, typically justifying premium multi-zone equipment over a basic swap. Mid-range inland heat here, 90 to 100 degrees common, is less extreme than El Cajon or Santee but still meaningfully warmer than the coast.
South Bay heating demand is modest, so furnace repair volume is lower here than inland, and most calls are routine ignition or thermostat-wiring issues priced at the county baseline. Gas furnaces and heat pump heating repair the same way here; we don't price one differently.
| Item | Typical cost | Notes |
|---|---|---|
| $89 diagnostic visit | $89 | Credited toward the repair once you approve the work |
| Hot-surface ignitor replacement | $250 - $500 | The most common reason a furnace won’t light |
| Flame sensor cleaning or replacement | $150 - $350 | Causes the furnace to shut off seconds after igniting |
| Inducer motor replacement | $400 - $800 | Furnace hums or clicks but won’t start the burner cycle |
| Gas valve replacement | $400 - $900 | Safety component, always tested before replacement is approved |
| Control board replacement | $400 - $800 | More common on furnaces with electronic ignition and diagnostics |
| Blower motor replacement | $450 - $900 | Furnace heats but airflow through the vents is weak or silent |
| Heat exchanger replacement | $1,500 - $3,500 | A safety-critical repair, often the point to consider a new furnace instead |
Ranges reflect Bonita and South County San Diego. Your exact figure depends on the factors below. We quote flat-rate before starting.
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.
For a 2,200 to 3,500 square foot Bonita estate home, expect $16,000 to $28,000 for a variable-speed heat pump replacement with two-zone control and smart thermostat integration. Larger equestrian properties with guesthouses or detached structures on the same parcel sometimes add a second smaller system, which adds to the total but keeps each zone properly sized rather than oversizing one system to cover everything.
South Bay heating demand is modest, so furnace repair volume is lower here than inland, and most calls are routine ignition or thermostat-wiring issues priced at the county baseline. Gas furnaces and heat pump heating repair the same way here; we don't price one differently.
$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.
Flat-rate pricing, confirmed before any work starts. Same-day scheduling on most calls.