What Furnace Repair Costs in Modesto (2026)

Updated 2026-10 · Modesto, CA

The short answer

Most furnace repairs that Modesto-area heating companies quote land between about $150 and $600, on top of or including a diagnostic visit that generally runs $80 to $150. The bigger parts (inducer motors, blower motors, gas valves, control boards) push a repair to somewhere between $400 and $1,500. A cracked heat exchanger usually means pricing a new furnace instead. We do not set any of these numbers and take no share of them; they are what local companies generally charge, and a quote well outside them is worth a question either way.

Part by part

Flame sensor, $100 to $250

The most common no-heat call of the first cold week. The furnace lights, cannot confirm the flame through a dirty sensor, and shuts the gas off. Usually a cleaning, sometimes a new sensor.

Igniter, $150 to $350

Hot-surface igniters are ceramic and crack with age. The part is inexpensive; most of the cost is the visit.

Pressure switch, $150 to $400

Confirms the inducer is venting properly before the gas opens. Sometimes the switch has failed; sometimes it is doing its job and the vent or condensate line is blocked, which is a different repair.

Inducer motor, $400 to $900

The small fan that clears the flue before ignition. A rising whine over a season or two usually precedes failure.

Control board, $300 to $800

The furnace's brain. Brand-specific boards for older units can take days to arrive, which is the real cost in November.

Blower motor, $450 to $1,200

Moves the air for heating and cooling. Variable-speed (ECM) motors cost more than the older fixed-speed type.

Gas valve, $350 to $900

Less common. The igniter glows, nothing lights, and the gas supply checks out.

What moves the price in Modesto

Where the furnace is

A garage furnace is the cheapest to work on. An attic furnace in a two-storey Village One or Salida house takes longer to reach and longer to work on, and that shows in the labour.

When you call

Evening, weekend and holiday calls cost more at most companies. The first cold week of November is the busiest week of the year for heating repair here; searches for furnace repair in Modesto ran at 720 in November 2025 against 90 in August 2026. A tune-up in September or October costs less than any repair and finds most of the parts above before they fail.

How old it is

Parts for a 25-year-old furnace can be slow to find and sometimes are not made any more. That can turn a $300 repair into a replacement conversation, which is a separate guide.

What a fair quote looks like

It names the part and the reason, gives the price before the work starts, and says whether the diagnostic fee is credited. If the diagnosis is a cracked heat exchanger, it comes with evidence: a camera image, a combustion reading, or a demonstration you can see. A quote that only says "furnace needs replacing" and nothing else is incomplete.

When the repair is not worth it

A large repair on a furnace past about 15 years old, or a second major repair in two winters, is where most people start comparing against a new furnace. In California that comparison has to include the permit, the energy code duct test, and any MID or TID rebate on a heat pump alternative, which narrows the gap more than people expect.

Where to go next

• Furnace repair in Modesto
• Repair or replace an older furnace
• Tune-ups that catch the cheap failures early