Call us
(650) 203-6702. Phone support is available 24/7.
Call first when something is failing right now, so we can sort out the symptom and send the right technician: no heat, no cooling, a burning smell, a breaker that trips when the system starts, water leaking from an indoor unit or through a ceiling below an attic unit, or a thermostat that has gone blank. See also emergency HVAC.
If you smell gas, do not use light switches or a phone inside the house. Leave first, then call your gas utility or 911 from outside.
Book online
Use the Book online button at the top of any page to choose the service and request an appointment. Online booking suits jobs that can wait a day or two: seasonal maintenance, a smart thermostat installation, a zoning project or an estimate for a new system. For anything urgent, call instead.
Office hours and address
| Day | Office hours |
|---|---|
| Monday to Friday | 6:30 AM to 9 PM |
| Saturday | 7 AM to 7 PM |
| Sunday | 8 AM to 5 PM |
| Phone support | 24/7 |
Address: Fremont HVAC Masters, 48501 Warm Springs Blvd, Fremont, CA 94539. Our technicians come to your home; this is our office address.
What to have ready
For a repair or maintenance visit:
- Equipment type: furnace, air conditioner, heat pump, mini-split or air handler.
- Brand, model and serial number if you can see them. They are on a label on the side of the outdoor unit, inside the furnace door or on the side of a mini-split’s indoor unit.
- The symptom and when it started: the noise, the smell, the room that stays warm.
- Any error code on the thermostat or indoor unit, or the blink pattern of the light on the furnace control board.
- What you have already checked: breakers, thermostat settings and batteries, the filter.
For a smart thermostat or zoning project:
- A photo of the current thermostat wiring with the cover off, showing which terminal letters have wires. Switch the system off first.
- Whether there is a C-wire: a wire on the C terminal, or a spare wire folded back behind the wall plate.
- The platform you use: Google Home, Amazon Alexa, Apple Home or SmartThings.
- Which rooms are uncomfortable and when, for example the upstairs bedroom in the afternoon. For zoning, also the number of floors and where the furnace or air handler sits.
Service area
We work in Fremont (94536, 94537, 94538, 94539, 94555), Newark (94560) and Milpitas (95035).