No heat or no cooling
Checking the thermostat call, outdoor unit, reversing valve and controls to find why the system runs but does not heat or cool.
Los Altos heat pump short cycling, frosting over or stuck on cold air? HAXX repairs ducted and ductless heat pumps in homes across the city.
Serving North Los Altos, Old Los Altos, South of El Monte, Loyola Corners and Woodland Acres and the rest of Los Altos. Share your address to confirm availability.

Ducted systems, ductless mini-splits and multi-zone heat pumps. Tell us what the system is doing and we start the visit with that symptom.
Checking the thermostat call, outdoor unit, reversing valve and controls to find why the system runs but does not heat or cool.
Some frost in winter is normal. A unit that stays iced points to airflow, refrigerant or defrost-control problems.
Blinking lights and error codes on Mitsubishi, Daikin, Fujitsu and other ductless systems, traced to the sensor, board or refrigerant issue behind them.
Units that start and stop, rattle, hum or trip the breaker are checked for electrical, airflow and sizing problems.
Clogged condensate lines and drain pumps cleared and tested before water damages the wall.
If the system is not worth fixing, you get the reasons in writing and options to compare, not pressure.
Los Altos homes range from 1950s ranch houses to new builds with basements and several zones. Each layout tends to fail in different places.
Larger rebuilt homes often run two or more systems or zones. HAXX checks dampers, thermostats and communication wiring, not just the outdoor unit.
Older attic and crawlspace ductwork can starve a newer heat pump of airflow. Static pressure and filter checks come before any part swap.
HAXX holds both C-20 HVAC and C-10 electrical classifications, so tripped breakers, disconnects and low-voltage faults are handled on the same call.
Rated 4.8 across 515+ reviews on Housecall Pro, Google and Facebook. Read more reviews.
“Their technician was professional, honest, and took the time to explain the problem and the repair process clearly. Instead of pushing for an expensive replacement, they repaired our HVAC system and helped us save a significant amount of money. The work was completed carefully, and our air conditioner is now working well.”
“Thorough diagnostics of A/C system, identified and repaired the issue quickly!”
“Service was performed well and on time. Service person was highly skilled and provided easy to understand options to deal with the issue. Price for diagnostics was reasonable and easy to pay online.”
Brand, model and what it is doing. Photos of the label or error code help.
The technician tests the system and finds the cause, not just the symptom.
You see the repair price before work starts, and the options if a repair is not worth it.
The repair is completed and tested, or scheduled once the part arrives.
A closer look at recent heating and cooling work by HAXX.

On site during a commercial VAV box repair: access above a suspended ceiling, equipment and the work in progress.
Explore recent projects
Heat pump air handler service.

Compressor replacement.

Mitsubishi leak detection.

After-hours system repair.

Heat pump installation.

Outdoor heat pump installation.

Heat pump air handler installation.

Lennox ac installation.
Common causes are a stuck reversing valve, a failed defrost board or sensor, or a low refrigerant charge. HAXX tests each before recommending a repair.
Yes. HAXX services air handlers wherever they sit, including attics, crawlspaces, basements and closets.
It depends on the fault, the refrigerant the system uses and the condition of the compressor and coils. HAXX explains the repair cost against replacement options so you can decide.
Yes. HAXX services wall, ceiling cassette and ducted mini-split heads, single-zone and multi-zone.
Share the property, equipment and questions you have in mind.
(408) 901-8315
Call HAXX to discuss your property and scheduling.
