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Furnace Repair in Los Altos, CA

The short answer

Most Los Altos furnace problems come from long idle stretches in our mild climate: dirty sensors, failed igniters, clogged filters, and worn blower parts. Repair is usually the right call for a sound furnace, and Bay Area Air District rules do not require replacing working equipment. If you do replace later, the rules point toward heat pumps, so it helps to plan ahead.

When the furnace in your Los Altos home won't start on a cold morning, or it runs but blows lukewarm air, you want a clear diagnosis and a straight answer about what it will take to fix. PerfectFix HVAC Services repairs gas furnaces throughout Los Altos and the 94024 ZIP code, driving over from our base in San Jose, about 14 miles east. This page covers what tends to go wrong with furnaces in this part of Santa Clara County, how we approach a repair, and how to decide between repairing and replacing under current Bay Area air rules.

Why Furnaces Act Up in Los Altos Homes

The Santa Clara Valley has a Mediterranean climate with dry summers and mild, damp winters. For a furnace, that means months of sitting idle, followed by a handful of chilly nights when it suddenly has to work. Many of the problems we see come from that stop-and-start pattern rather than from heavy, constant use.

Dust settles on burners and sensors during the off-season, filters get forgotten, and small parts like igniters and flame sensors often fail on the first cold start of the year. Damp winter air can also add to corrosion on older components and venting. Common signs your furnace needs attention:

  • The furnace clicks or lights, then shuts off after a few seconds
  • The blower runs, but the air from the vents is cool
  • Short cycling, where heat turns on and off every few minutes
  • Banging, squealing, or rattling when the system starts
  • A burning-dust smell that doesn't fade after the first few hours of use
  • The thermostat calls for heat and nothing happens at all

How We Handle a Furnace Repair Visit

We start with the basics that are easy to overlook: thermostat settings and batteries, the filter, the service switch and breaker, and the gas supply. Then we walk through the ignition sequence step by step, checking the inducer motor, pressure switch, igniter, flame sensor, gas valve, and blower to find exactly where it stops.

Once we know the cause, we explain it in plain terms, show you the part if that helps, and go over your options before doing any work. If a part has to be ordered, we tell you up front and leave the system in a safe state until we return.

We also look at the heat exchanger, venting, and combustion during the repair, because a furnace that lights is not necessarily a furnace that's running safely.

Repair or Replace? What Bay Area Rules Mean for You

Bay Area Air District rules are changing what furnace replacement looks like. Under Rule 9-4, natural gas furnaces manufactured from 2029 on must meet a zero-NOx emission standard, which in practice points homeowners toward heat pumps when a furnace is replaced after that date.

The rules do not force anyone to remove a working furnace. They apply only when an existing furnace fails or is replaced. If your furnace is in good shape and the repair is reasonable, fixing it is often the sensible move.

If your furnace is older and repairs keep adding up, you may want to plan a change on your own schedule rather than wait for a mid-winter breakdown. A few things to keep in mind:

  • The federal 25C tax credit covered qualifying heat pumps placed in service before December 31, 2025. It isn't available for new installations now.
  • BayREN and your local clean energy provider may offer heat pump and electrification incentives. Amounts and availability change by funding cycle, so we confirm the current offer before including it in a quote.
  • If you're also thinking about your gas water heater, the zero-NOx date for small water heaters under Rule 9-6 was set for 2027. The Air District Board is considering amendments in November 2026 that could delay it, so check the current rule before planning that replacement.

Safety Comes First

If you smell gas, leave the house, don't operate light switches or appliances, and call your gas utility or 911 from outside. Don't try to relight a furnace you suspect is leaking.

Every home with a gas furnace should have working carbon monoxide alarms. If an alarm sounds, or people in the house have headaches or nausea that ease when they step outside, get everyone out and call emergency services before calling us.

Serving Los Altos and Nearby Communities

We repair furnaces in homes across Los Altos, ZIP 94024, and in nearby Los Altos Hills, Mountain View, Sunnyvale, Cupertino, and Santa Clara. When you contact us, describe what the furnace is doing, note any blinking codes on the control board, and tell us roughly how old the unit is. That information helps us arrive with the right parts and fix the problem sooner.

More services in Los Altos

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What to expect

How a visit goes

  1. Clear Explanations

    We show you what's wrong, explain why it matters, and describe your options in plain language so you can make the call that fits your home and budget.

  2. Repair First When It Makes Sense

    If a repair will keep your system running reliably, we'll say so. We recommend replacement only when it's the more practical choice for your situation.

  3. Respect for Your Home

    We protect floors and work areas, keep our work tidy, and walk you through what we did before we leave.

FAQ

Common questions

Don’t see your question? Call (669) 272-3348 and we’ll talk it through.

Why does my furnace smell like burning when I first turn it on?

After months of sitting idle, dust collects on the burners and heat exchanger and burns off at the first startup. The smell should fade within a few hours. If it lingers, smells electrical, or comes back every time the furnace runs, turn the system off and have it checked.

Do I have to replace my gas furnace because of the new Bay Area rules?

No. The Bay Area Air District rules do not require replacing working equipment. They apply only when an existing furnace fails or is replaced. Gas furnaces manufactured from 2029 must meet a zero-NOx standard, which in practice points toward heat pumps for replacements after that date.

Can I still get the federal tax credit for a heat pump?

Not for new installations. The federal 25C credit covered qualifying heat pumps placed in service before December 31, 2025. Check BayREN and your local clean energy provider for current incentives, and we'll confirm what's available before we quote it.

Is my furnace worth repairing?

It depends on the condition of the heat exchanger, the furnace's age, how often it has needed repairs, and what the current repair involves. We'll walk you through what we find so you can make the call. A single failed igniter or sensor on a sound furnace is usually worth fixing.

How often should I change my furnace filter?

Follow the filter manufacturer's guidance and check it at the start of the heating season and regularly while the furnace is in use. A clogged filter restricts airflow and is a common cause of overheating, short cycling, and weak heat.

Do you also repair furnaces outside Los Altos?

Yes. Along with Los Altos, we serve Los Altos Hills, Mountain View, Sunnyvale, Cupertino, and Santa Clara from our base in San Jose.

Need Heating or Cooling Help?

Tell us what's going on with your system, and we'll schedule a visit to diagnose the problem and walk you through your options.

(669) 272-3348
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