5040 Commercial Circle, Unit C
Concord, CA 94520
(925) 438-8367

Have any feedback for us? We'd love to hear it! Call us at (925) 326-6232 and let us know how we are doing.


Local Reviews
for los altos, ca

Rated 5.0 out of 5 stars based on 1 customer reviews

Thorough service

I was busy in a Zoom class while he was here, but got up a few times and was happy with what he was doing.

  • Overall Experience
  • Quality
  • Price
  • Convenience

Job Locations
for los altos, ca

Eric C.

Eric C. Job Checkin

Air Conditioning installation and furnace replacement in Los Altos.

Air Conditioning installation and furnace replacement in Los Altos.

Galen  S.

Galen S. Job Checkin

I am in Los Altos, California to look at adding air conditioning to 2 central heating systems for a chiropractic center.


Diego C.

Diego C. Job Checkin

In Los Altos this afternoon doing a furnace maintenance and a dryer vent cleaning for the Connell residence. They’ll be nice and warm this winter after this maintenance. Dryer vent also cleared out to prevent any house fire.

In Los Altos this afternoon doing a furnace maintenance and a dryer vent cleaning for the Connell residence. They’ll be nice and warm this winter after this maintenance. Dryer vent also cleared out to prevent any house fire.

Brittany B.

Brittany B. Job Checkin

Discussing replacement options with Certified member who decided to move forward with replacement. We will soon be installing a new, for more efficient system and look forward to bringing client comfort for many years to come. Thank you for choosing Certified!

Discussing replacement options with Certified member who decided to move forward with replacement. We will soon be installing a new, for more efficient system and look forward to bringing client comfort for many years to come. Thank you for choosing Certified!

Chris  R.

Chris R. Job Checkin

Building estimate for solar system for client, with rooftop installation on cottage


Chris  R.

Chris R. Job Checkin

Performed tune up on air conditioner, cleaned filter and outdoor unit. Checked capacitor, contactor, electrical connections, refrigerant levels and amperage draw on compressor, condenser fan motor and blower. Found system not designed properly, 3 ton upflow furnace in garage with 3 ton evaporator coil and 3.5 ton condenser outside. Refrigerant level is fine but not working correctly indoor unit is flooding with refrigerant and outdoor unit is starving of refrigerant due to lack of airflow from undersized furnace and coil. Compressor is using a large amount of energy due to system not designed properly. System cools but not the way it should or how it will with a new properly designed system for the home.


Brittany B.

Brittany B. Job Checkin

Performing AC maintenance on 2 systems, both 1998 Bryant condensers, for one of our certified members in Los Altos Hills. Cleaned up and tested refrigerant levels, inspected and tested safety and electrical components and made recommendations as needed. One system is struggling at this time, compressor motor is making a loud noise and pressures are fluctuating indicating that there may be noncondensibles in the refrigerant lines - no filter line drier in place.

Performing AC maintenance on 2 systems, both 1998 Bryant condensers, for one of our certified members in Los Altos Hills. Cleaned up and tested refrigerant levels, inspected and tested safety and electrical components and made recommendations as needed. One system is struggling at this time, compressor motor is making a loud noise and pressures are fluctuating indicating that there may be noncondensibles in the refrigerant lines - no filter line drier in place.

Yvonne G.

Yvonne G. Job Checkin

Furnace as tune up

Furnace as tune up

Yvonne G.

Yvonne G. Job Checkin

Furnace tune up and AC tune up

Furnace tune up and AC tune up