Belmont HVAC Company handles the full range of heating and cooling work for homes, rental properties, and commercial spaces across Belmont and San Mateo County. Whether a system has stopped working entirely or is just not keeping up, we scope the problem on the phone before anything is scheduled. Heat pumps, furnaces and mini-splits all within scope. No guesswork. No shortcuts. No rushed diagnosis.
Call (650) 879-8929 for a quote. We are open every day from 5:30 AM to 8:00 PM.
From a quick tune-up to a whole-system replacement, the diagnosis comes first, because throwing parts at a system that needs a different fix wastes time and money. When an air conditioner stops cooling, a furnace refuses to turn on, or a heat pump is running but not moving the needle on the thermostat, the first step is understanding why.
We handle AC repair and service, heating and furnace repair, heat pump service, and the full range of comfort calls that homeowners, landlords, and property managers deal with throughout the year. Uneven temperatures between rooms, a condenser that cycles on and off without completing a cooling run, a blower that runs but pushes weak airflow through the registers, a compressor that trips the system off on a hot afternoon: these are the kinds of problems this service is built to diagnose and fix.
Commercial and rental-property calls are welcome. An office building, a retail space, or a multi-unit apartment building has the same basic need as a single-family home: a system that works when it is supposed to. HVAC service booked around your schedule, whether that means early morning or a weekend slot.
Reach out and we will talk through the symptoms.
From aging systems to brand-new installs, the conversation starts with what the space actually needs, not with a product recommendation made before anyone has looked at the equipment. If a system is old enough that repair costs are stacking up, or if it simply cannot keep pace with what the home demands, a full replacement is often the more practical path.
We handle complete HVAC system replacement, central air installation, and full system installs for residential and commercial properties. When cost is the first question on the call, we answer it directly. You get the price before anything is scheduled, and you know what the visit covers before we book it. A written scope on installation work is part of how we handle these jobs, so there is no ambiguity about what is included.
New system installs also open the door to energy-efficiency upgrades: a higher-efficiency air handler, a zoning configuration that lets different parts of the house run at different temperatures, or a system sized correctly for the square footage rather than a guess. Sizing matters more than most people realize. An oversized unit short-cycles and wears out faster. An undersized one runs constantly and still does not hit the set point.
One call is all it takes to get it looked at.
Belmont sits in the coastal fog belt of San Mateo County, where the climate is mild enough that many older homes were built without any cooling system at all. That is changing. Heat events that used to be rare are arriving more often, wildfire smoke from inland fires now reaches the Peninsula regularly, and California's energy policy is pushing hard toward heat pump electrification. The three services below come up constantly in this area for exactly those reasons.
Questions about the equipment get answered before anything is booked.
A large share of Belmont's housing stock predates the era when central air was standard on the Peninsula. Adding cooling to a home that has never had it does not always mean tearing into walls and ceilings to run new ductwork. Mini-split and ductless systems mount on the wall or ceiling and connect to a compact outdoor unit, making them a practical fit for older homes, additions, and spaces where existing ductwork does not reach.
Before recommending a system size or configuration, we assess the home's layout and the state of any existing ductwork. A house with good ducts and a compatible air handler may be a candidate for central AC. A house without ducts, or with ducts that would need significant work, is often better served by a ductless installation. The right answer depends on the building, not on what is easiest to install.
Call for a quote and we will walk through the options for your home.
Wildfire smoke carries fine particulate matter that standard one-inch filters are not rated to capture. A MERV-13 or higher-rated filter stops particles that pass straight through a MERV-8, and the difference is measurable during a smoke event. For households with respiratory conditions, the upgrade is not a luxury.
The visit covers a check of the existing air handler and filter housing to confirm compatibility, because not every system can pull air through a denser filter without straining the blower. Where the existing equipment supports it, we upgrade the filtration media. Where it does not, we discuss what the options are. Whole-home air filtration, air purifier installation, and indoor air quality inspections are all part of this work.
A heat pump moves heat rather than generating it, which makes it efficient in climates where temperatures rarely drop to extremes. Belmont's mild winters are exactly the conditions where a heat pump performs well. A single outdoor unit handles both heating in winter and cooling in summer, replacing what would otherwise require two separate systems.
California's incentive environment for heat pump installation has made the economics more favorable than they were a few years ago. We handle heat pump installation, heat pump replacement, and heat pump service for existing systems that need attention. The scope and the price are confirmed on the call before anything is scheduled. We speak to the equipment and its installation. The electrical side of a new circuit or disconnect is a separate trade.
Choosing the right HVAC fix is easier than it sounds, once the system has been looked at properly. A room that never reaches the set temperature is not always a sign that the equipment is failing. Leaking or disconnected ductwork can bleed conditioned air into an attic or crawl space before it ever reaches the register. Duct sealing addresses exactly that: air that is paid for but never delivered to the living space.
We handle ductwork repair and sealing, ductwork replacement, and ductwork inspection for homes where airflow has become uneven or where energy use has crept up without an obvious cause. An evaporator coil that has not been cleaned in several seasons, a refrigerant leak that causes the system to run long without cooling effectively, a blower that is moving less air than it should: these are the details that a proper inspection surfaces.
Thermostat installation, including smart thermostat and programmable control upgrades, is a straightforward job that can change how a system behaves throughout the day. A thermostat that reads the temperature incorrectly, or one that is located in a spot that gets direct sun, will run the system in ways that do not match what the rest of the house needs.
Seasonal maintenance keeps systems running as they should. A spring AC tune-up before the warm months, a fall furnace tune-up before heating season, or an annual check that covers both: ask what the visit covers and you get a straight answer before anything is booked.
We will look at the system and tell you what it needs.
Getting your comfort back is easier than you think. When a furnace stops working in the middle of the night or an air conditioner quits on the hottest afternoon of the year, the first call gets you someone who can scope the problem on the phone. The price is discussed before anything is scheduled, and the system is tested before the visit ends.
We take emergency and urgent calls every day from 5:30 AM to 8:00 PM. No heat in the house, no cooling, a system that has shut down without warning: these are exactly the calls we handle. The scope is confirmed on the phone so you know what the visit covers before anyone arrives.
Ready for your system. Call now.
The work we do in Belmont extends across San Mateo County and the surrounding Peninsula communities. We regularly handle heating and cooling calls in San Carlos, Redwood City, San Mateo, Foster City, Burlingame, Millbrae, Hillsborough, and Half Moon Bay. If your property is in the area, call and we will confirm coverage when you reach out.
A system that runs without cooling is one of the most common calls we handle, and the cause varies more than most people expect. Refrigerant loss, a fouled evaporator coil, a failing compressor, or a condenser coil clogged with debris can all produce the same symptom from the inside of the house. The diagnostic visit identifies which part of the system is responsible before any repair is quoted.
The visit starts with a full assessment of the system: airflow, refrigerant charge, electrical connections, coil condition, and how the controls are communicating with the equipment. We work through the system from the thermostat to the outdoor unit rather than replacing parts based on the most common cause of a symptom. That approach finds the actual fault instead of the most likely one.
After a repair or installation, the system is run through its operating cycle to confirm the fault has been resolved and the equipment is performing as it should. On a cooling call, that means checking supply air temperature and airflow at the registers. On a heating call, it means confirming the heat exchanger is firing and the blower is distributing air correctly. The system tested before the visit ends is how we confirm the work, not how we hope it went.
A furnace that takes multiple attempts to ignite, one that cycles on and off without reaching the thermostat set point, or one that produces noticeably less heat than it used to are all signs the system needs attention. A cracked heat exchanger is a more serious concern and often shows up as a burning smell or carbon monoxide detector activity. Any of those symptoms is a reason to call before the heating season puts the system under full demand.
A heat pump that blows cold air in heating mode, one that runs constantly without reaching temperature, or one that switches between heating and cooling on its own are common signs of a problem. Reversing valve faults, refrigerant loss, and defrost cycle failures are the most frequent causes in this climate. A diagnostic visit identifies which it is and whether repair or replacement is the better path.
The installation involves mounting an air handler on the interior wall or ceiling of the room being conditioned, placing a compact outdoor condenser unit outside, and connecting the two through a small penetration in the wall with a refrigerant line set and low-voltage wiring. We handle the equipment installation and the low-voltage connections between the indoor and outdoor units. The household electrical circuit and disconnect are handled by an electrician working alongside the installation.
The visit starts with a check of the existing air handler and filter housing to confirm what the system can support. A standard one-inch filter slot may need a media upgrade or a filter cabinet addition to hold a MERV-13 or higher filter without straining the blower. Where the duct system allows it, a whole-home air scrubber or UV purifier can be added alongside the filtration upgrade. The options are walked through on the visit based on what the existing equipment can accommodate.
The job covers removing the existing heating unit, installing and commissioning the heat pump, and connecting it to the existing air distribution system or configuring new air handlers where the home does not have ductwork. We handle the equipment and the air-side installation. The electrical circuit and disconnect that a new heat pump requires are outside our scope and are handled by an electrician. The written scope on the installation makes clear what each trade is responsible for before the job starts.
Either one can produce the same symptoms: rooms that do not reach temperature, uneven airflow between floors, or a system that runs longer than it should. A duct system with significant leakage loses conditioned air before it reaches the register, which makes the equipment look like it is underperforming when the ducts are actually the problem. The diagnostic visit checks both, so the repair addresses the actual cause rather than the most visible one.
A repair makes sense when the fault is isolated, the equipment is not at the end of its service life, and the cost of the fix is reasonable relative to what a replacement would run. When repair costs are recurring, the system is old enough that efficiency has dropped significantly, or the equipment cannot meet the load the space demands, replacement is usually the better investment. We walk through both options where both apply, and the decision is yours once you have the numbers.
A spring AC tune-up covers refrigerant charge, coil condition, electrical connections, drain line clearance, and airflow through the system. A fall furnace tune-up covers the heat exchanger, igniter, blower motor, filter, and flue. The goal in both cases is to find what is marginal before it becomes a failure, because a component that is starting to degrade shows up in a tune-up and not in an emergency call.
On repair calls, the scope of what was done is confirmed with you before the technician leaves. On installation work, the written scope agreed before the job starts is the baseline for what the invoice reflects. Ask what the documentation covers when you call and you get a straight answer before anything is scheduled.
Rooftop units and exterior packaged systems are diagnosed the same way as residential equipment: the fault gets identified before a repair is quoted, and a replacement gets sized to the load before anything is ordered. Commercial rooftop work is part of the regular scope for office buildings, retail spaces, and multi-unit properties across San Mateo County. The price and the visit details are confirmed on the call before anything is booked.
System tuned. Airflow balanced. Home comfortable.
Belmont HVAC Company is available every day from 5:30 AM to 8:00 PM for residential and commercial heating and cooling calls across Belmont and San Mateo County. Whether you are a homeowner dealing with a system that stopped working, a landlord managing a repair at a rental property, or a property manager handling a commercial space, the process is the same: call, get the scope on the phone, and get the price before anything is scheduled.
Call (650) 879-8929 for a quote.
We handle the full range of heating and cooling work in Belmont and across San Mateo County, from a single-room ductless install to a whole-system replacement on a commercial property. The table below covers every service we offer, who it fits best, and what is worth knowing before you call. If you have questions about a specific job, call us and we will talk through what the work involves before anything is scheduled.
| System Service | What the Service Includes | Best For | What to Keep in Mind |
|---|---|---|---|
| AC Repair & Service |
| Homeowners or property managers with a system that has stopped cooling or is underperforming | A system that runs but does not cool often has a refrigerant, coil, or compressor issue rather than a simple part failure. Diagnosis comes before any repair quote. |
| Heat Pump Repair & Service |
| Homes in Belmont already running a heat pump that is not reaching temperature or switching modes incorrectly | Belmont's mild winters are well suited to heat pump operation. A system that blows cool air in heating mode often has a reversing valve or refrigerant fault. |
| Heat Pump Electrification |
| Belmont homeowners replacing a gas furnace or older AC and looking to move to an all-electric heating and cooling system | California's incentive environment has made heat pump electrification more cost-competitive. The electrical circuit and disconnect are handled as part of the installation scope. |
| Full System Installation & ReplacementMost Popular |
| Homeowners whose system is aging, repeatedly failing, or unable to keep pace with the home's demands | An oversized unit short-cycles and wears out faster. An undersized one runs constantly. Correct sizing is confirmed before equipment is ordered. |
| Heating & Furnace Repair |
| Households where the furnace is not igniting, cycling off early, or producing less heat than expected | Fall is the busiest window for furnace calls. Scheduling before the first cold stretch means shorter waits and a system ready when temperatures drop. |
| Seasonal Maintenance & Tune-Ups |
| Homeowners who want to catch a marginal component before it becomes an emergency call | A spring AC tune-up and a fall furnace tune-up are the two most common schedules. Either visit can surface a developing fault before the peak season puts the system under full demand. |
| Indoor Air Quality & Air Filtration |
| Households dealing with dust, allergens, wildfire smoke, or occupants with respiratory sensitivities | Filtration upgrades are most effective when the air handler and duct system are assessed together. A filter upgrade that strains the blower can reduce airflow across the whole system. |
| Ductwork Repair & Sealing |
| Homes with uneven temperatures between rooms or energy bills that have crept up without an obvious cause | A duct system with significant leakage loses conditioned air into the attic or crawl space before it reaches the register, making the equipment look like the problem when the ducts are. |
| Wildfire-Smoke Air Filtration (MERV-13+) |
| Bay Area households with respiratory concerns or homes that experienced smoke infiltration during fire events | Not every air handler can pull air through a denser filter without straining the blower. We check compatibility before upgrading the filtration media. |
| Thermostat & Smart Controls |
| Homeowners who want better schedule control or whose current thermostat is reading inaccurately | A thermostat placed in direct sunlight or near a heat source will run the system in ways that do not match the rest of the house. Location matters as much as the unit itself. |
| Ductless Mini-Split Installation |
| Older Belmont homes without existing ductwork, additions, or spaces where central air cannot reach | Many Peninsula homes built before the 1980s have no duct system. A mini-split avoids the cost of running new ductwork through finished walls and ceilings. |
| Emergency HVAC Service |
| Any household or commercial property where the heating or cooling system has stopped working entirely | We take emergency calls every day from 5:30 AM to 8:00 PM. The scope and the price are discussed on the phone before anyone is sent out. |
How often should I schedule HVAC maintenance and tune-ups?
Once a year covers most systems. If you run both heating and cooling, a spring tune-up before the warm months and a fall tune-up before heating season is the better approach. Each visit checks different components, and catching a marginal part in a tune-up is considerably less disruptive than catching it in an emergency call on the coldest night of the year.
What are the signs that a system has a refrigerant or airflow problem?
A system that runs long cycles without reaching the thermostat set point, one that produces warm air from the supply registers during a cooling call, or one where ice forms on the indoor coil are all common signs of a refrigerant or airflow issue. Low refrigerant and a restricted coil produce similar symptoms from inside the house, which is why the diagnostic visit checks both before a repair is quoted.
How do I decide between repairing my current system and replacing it?
The short answer is cost relative to the remaining life of the equipment. A repair that costs a fraction of a replacement makes sense when the system is not at the end of its service life and the fault is isolated. When repair costs are recurring, the system is old enough that efficiency has dropped significantly, or the equipment cannot meet the load the space demands, replacement is usually the better investment. We walk through both options where both apply, and the decision is yours once you have the numbers.
Diagnosis Explained Before Any Repair
We identify the fault before quoting a repair, and we walk you through what we found in plain terms. You know what the problem is and what fixing it involves before any work is approved.
Why is one room in my home hotter or colder than the rest?
Uneven temperatures between rooms usually point to one of three things: a duct system that is leaking or improperly balanced, a system that is not sized correctly for the square footage it serves, or a thermostat placement issue that causes the system to read the temperature in one part of the house and ignore the rest. A diagnostic visit checks all three rather than assuming the equipment is the cause.
What can strange noises from an HVAC unit mean?
A banging or clanking noise often points to a loose or failing blower wheel or motor mount. A high-pitched squealing sound is commonly a belt or bearing issue. A clicking that continues after the system starts can indicate a failing relay or control board. A rattling from the outdoor unit during a cooling call sometimes means debris has gotten into the condenser housing. None of these are self-diagnosing from the sound alone, but any persistent new noise is worth a call before it becomes a full failure.
How does a dirty filter or coil affect system performance?
A clogged filter restricts the airflow the system needs to move conditioned air through the house, which forces the blower to work harder and reduces the volume of air reaching the registers. A dirty evaporator coil insulates the refrigerant from the air it needs to absorb heat from, which causes the system to run longer without cooling effectively. Either condition raises energy use and accelerates wear on the equipment. Both are checked during a tune-up visit.
Older Systems and New Installs Both Covered
Whether the system is a decades-old furnace that needs attention or a brand-new heat pump going in for the first time, the scope is the same: assess what is there, confirm what the job covers, and do the work correctly.
What does a thermostat or smart-control upgrade actually involve?
The visit covers removing the existing thermostat, confirming the wiring at the wall is compatible with the new unit, installing and pairing the new control with the system, and verifying that both heating and cooling modes respond correctly. Placement matters too. A thermostat in direct sunlight or near a drafty window reads the temperature inaccurately and runs the system in ways that do not match what the rest of the house needs. We check placement as part of the visit.
Do I need to be home when the HVAC work is done?
For most visits, yes. Access to the equipment, the filter housing, the outdoor unit, and in many cases the attic or crawl space is part of the job. On installation work, someone with authority to confirm the scope and sign off on the work should be available at the property. If scheduling around a work day is a concern, ask about early morning slots when you call. We book around your schedule where the calendar allows.
Emergency No-Heat and No-Cool Calls Handled
We take urgent calls every day from 5:30 AM to 8:00 PM. The scope and the price are discussed on the phone before anyone is sent out, so there are no open questions when the visit starts.
How long does a full system replacement typically take?
A standard residential replacement, one outdoor unit and one air handler with existing ductwork in place, typically runs most of a day. A more complex job, such as a home without existing ductwork or a commercial property with rooftop equipment, takes longer. The written scope on installation work covers the timeline as well as what is included, so you know what to expect before the job starts.
What causes a system to short-cycle, and is it a serious problem?
Short-cycling means the system turns on, runs briefly, shuts off, and repeats without completing a full heating or cooling cycle. An oversized unit is one common cause. A refrigerant problem, a failing compressor, or a thermostat fault can produce the same behavior. Short-cycling is worth addressing promptly because the repeated start-stop puts more wear on the compressor than a normal run cycle does.
Is older equipment worth repairing, or should I plan for replacement?
Age alone is not the deciding factor. A well-maintained older system with an isolated fault and a reasonable repair cost is often worth fixing. The case for replacement gets stronger when the system requires refrigerant that is no longer widely available, when efficiency has dropped to the point where operating costs outweigh the repair savings, or when the equipment is failing in multiple places at once. We give you both options where both apply.
Call us at (650) 879-8929 to talk through your system, get a price, and find out what the visit covers before anything is scheduled.
(650) 879-8929