Furnace and heating repair in San Diego, CA

San Diego's coastal climate is mild, and the heating season is short and light. Furnaces near the coast may run only on cool nights and winter mornings. Inland neighborhoods and the foothills get colder nights and use their heat more.

Light use has a side effect. A furnace that rests for most of the year meets its first cold night with dust on the burners, a filter still loaded from summer and parts that have not moved in months. Many heating calls here come down to that first start. Older homes may have a wall furnace or floor furnace in place of a ducted central system, and those need a technician who works on them regularly.

Heat pumps suit this climate well and are a common choice when homeowners add cooling. If your outdoor unit runs in heating mode, see the heat pump not heating guide for the likely causes.

Run through these first. They are the only checks that are safe without opening the equipment.

• Set the thermostat to Heat, raise the setpoint a few degrees above room temperature and replace the batteries if it has them.
• Check the breaker panel for a tripped breaker on the furnace, air handler or heat pump. Reset it once. If it trips again, stop and call.
• Find the power switch on or near the furnace or air handler, which looks like a light switch, and make sure it is on.
• Pull the filter. If it is gray and matted, replace it. A clogged filter can make the system overheat and shut itself off.
• Open the supply registers and clear furniture or rugs away from the return grille.
• Clear leaves and debris from around the outdoor unit if you heat with a heat pump.
• Write down any error code on the thermostat or the blinking light pattern visible through the furnace's sight window.

The technician confirms the symptom, reads any fault code and tests the likely parts. For a gas furnace that usually means the igniter, flame sensor, pressure switch, inducer motor, limit switches and blower. For a heat pump it means capacitors, the contactor, the reversing valve, the defrost control and the refrigerant charge.

Expect a diagnosis and a written price before the repair starts. Ask what failed and why, and whether the part is covered by a manufacturer warranty. Ask to see the failed part.

California contractors are licensed by the Contractors State License Board (CSLB), and heating work falls under the C-20 classification. Look up the company with CSLB's Check a License tool before the visit; the California license lookup guide shows what to read on the record. CSLB says C-20 contractors must carry workers' compensation or have a self-insurance certification on file.

A part replacement is a repair. Replacing the furnace or installing a heat pump is a bigger job: CSLB says most alterations require a permit from the local building official and that requirements vary by city and county. If the visit turns into a replacement in San Diego, CSLB's guidance is to get at least three written bids, and a home improvement down payment should not exceed 10 percent of the price or $1,000, whichever is less.

For a furnace that runs only a few weeks a year, repairing a single failed part is usually sensible. Replacement comes up when the heat exchanger is cracked, when an old wall or floor furnace can no longer be repaired safely, or when you plan to add AC and one heat pump could cover both needs.

If you smell gas or a CO alarm has sounded, do not wait for an appointment. Leave the house and follow the steps on the emergency furnace repair page.