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Heating Repair for Los Altos Households

The short answer

We repair furnaces, heat pumps, wall and floor heaters and ductless systems in Los Altos. Tell us what kind of heating you have and what it is doing, and we will diagnose the fault, explain the options and fix it.

Not every home in Los Altos heats the same way. Some have a forced-air gas furnace, some have a newer heat pump, others still rely on a wall heater, a floor furnace or a ductless system added during a remodel. When the house stays cold, the right fix depends on which of these you have. ReliableAir HVAC Services repairs all of them across ZIP 94024, a short drive of about 9 miles west from our San Jose shop. This page is organized by heating type, so you can jump to the part that matches your house and know what to expect before a technician arrives.

Forced-air furnaces

This is the most common setup in town. When a furnace stops heating, the cause is usually somewhere in its ignition chain: igniter, flame sensor, pressure switch or gas valve. Less often it is the control board or a wiring fault. A furnace that runs but leaves rooms cool may have an airflow problem, such as a clogged filter, a loose duct in the attic or a weak blower.

We start every furnace call by reading any fault code, then run the furnace through a full heating cycle while measuring temperature rise and checking the flame and vent draft. That way the repair addresses the actual failure, not just the symptom.

Heat pumps in heating mode

Heat pump owners sometimes worry when the outdoor unit goes quiet and then steams on a damp morning. That is a defrost cycle and is normal. Real heating problems look different: the indoor air feels cool for long periods, the backup heat runs constantly, or the outdoor unit ices over and stays that way.

Common causes include a stuck reversing valve, a failed defrost sensor or control, low refrigerant from a leak, and outdoor coils packed with leaves. Because heat pumps produce gentler warmth than a furnace, thermostat settings matter too; a setup intended for a gas furnace can make a heat pump seem underpowered.

  • Outdoor coil iced over for more than an hour
  • Emergency or auxiliary heat light staying on
  • Air from registers feels lukewarm even after a long run time
  • Grinding, rattling or loud buzzing from the outdoor unit

Wall heaters and floor furnaces

Older Los Altos houses and some cottages still have gravity wall furnaces or floor furnaces. These are simple appliances, but age catches up with them. Thermocouples fail, pilot assemblies clog, and gas valves wear out. We repair these units when parts are available and safe to install.

We also check clearances and venting closely. Wall and floor heaters sit inside living spaces, so a cracked combustion chamber or a poorly drafting vent is a real concern. If one of these units is beyond safe repair, we explain the alternatives, which often include a ductless heat pump that heats and cools the same rooms.

Ductless mini-split heating

Mini-splits report problems through blinking lights or error codes on the indoor head. Typical causes include a dirty indoor filter, a blocked condensate line that triggers a shutoff, a failed temperature sensor, or a communication fault between the indoor and outdoor units. We read the code with the manufacturer's service data and test the components it points to.

Thinking about the next system

Repair is usually the right first step. There are moments, though, when it makes sense to look ahead. The Bay Area Air District rules do not require replacing working equipment, but under Rule 9-4, gas furnaces manufactured from 2029 must meet a zero-NOx standard, which in practice points replacements toward heat pumps. If your furnace or wall heater is near the end of its life, we can price a repair and an electric alternative side by side.

The federal 25C credit for heat pumps ended for systems placed in service after 2025. Local incentives through BayREN or your clean energy provider may be available; they change by funding cycle, and we confirm them before quoting. Our heating repair service also covers Los Altos Hills, Mountain View, Palo Alto, Sunnyvale and Cupertino.

More services in Los Altos

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What to expect

How a visit goes

  1. Test, then talk

    Readings come first. You hear the cause of the problem and see the evidence before any part is replaced.

  2. Options, not pressure

    When repair and replacement are both reasonable, we lay out each path and let you choose the one that fits your home and plans.

  3. Respect for the house

    Shoe covers, drop cloths and a cleared work area. Attics, closets and side yards are left the way we found them.

FAQ

Common questions

My heat pump is blowing cool air in heating mode. Is it broken?

Heat pump air feels cooler than furnace air, which is normal. If it stays cool for a long time or the backup heat runs constantly, there may be a refrigerant, valve or defrost problem worth checking.

Can you repair an old wall furnace?

Often yes, as long as safe replacement parts are available and the combustion chamber and vent are in good condition. If not, we explain replacement options.

What should I tell you when I call about a heating problem?

Let us know the type of heating system, what it is doing, any codes or lights you see, and when the problem started. That helps us bring the right parts.

Why is one room always colder than the rest?

Common causes include a disconnected or crushed duct, a closed damper, poor insulation in that room, or a return air problem. We measure airflow to find the cause.

Is it worth repairing an older furnace?

Usually, if the heat exchanger is sound and the repair is moderate. We compare the cost of the repair with the furnace's age and condition so you can decide.

Tell us what your system is doing

Describe the noise, smell, error code or temperature problem, and we will set up a visit to find the cause and talk through your options.

(669) 666-6071
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