HVAC and Solar Services Serving All of Solano, Napa & Contra Costa Counties, and the Bay Area

Our Reputation speaks for Itself

A-1 Guaranteed is a family-owned and operated business that serves HVAC and Solar Services Serving All Of Solano, Napa and Contra Costa Counties, Fairfield, Vacaville, and the Bay Area with Heating and Air Conditioning, Solar, Tankless Water Heaters, Windows, Insulation and/ or Duct Replacement needs. As one of the premier service businesses in the area, we have helped thousands of satisfied, loyal customers improve the energy efficiency of their homes and offices.

We are available Monday through Friday and by appointment on Saturday. Our fast and efficient attention to your needs will prove our dedication to our customers is the foundation of our business. Our professional staff is knowledgeable and looks after your best interests when it comes to your environmental comfort needs. We are an Energy Upgrade CA participating contractor. We are honored that our customers consider us #1 in providing trustworthy service and dependable comfort.

Why Choose

A-1 Guaranteed?

  • Voted best heating/cooling company for 14 years
  • Voted Best of The Bay for 5 years of KRON 4 TV
  • Commercial and Residential Installation
  • Angie’s List Super Service Award for 2 Years
  • Energy Upgrade Participating Contractor
  • Factory Trained Installers and Techs
  • Drug-free Environment Enforced and Maintained
  • Better Business Bureau Honor Roll 20 Years
  • Diamond Certified Company
  • North American Technician Excellence (NATE) certified
  • Bay Area Certified Green Business
  • All employees fully background checked for your safety
Recent News


Thinking of Going Solar? Here’s Why You Should

The benefits of using solar energy to power your home can’t be understated – it’s an exhaustive list of how the sun can benefit you, your family, your home, your community, and the globe. Solar energy is renewable, plentiful, and sustainable, and the cost of producing electricity this way decreases every year. There are now millions of solar installations across the country, with more being added every day.

If you’ve been contemplating going solar and are searching for solid reasons to do so, read on.

Solar Energy Means Drastic Savings

Most people are aware that solar energy saves big money when it comes to utility bills, but did you know that in many cases, electric companies will pay homeowners who use solar energy money? This is because some homeowners actually contribute energy to “the grid”, so the electric company pays them for it, instead of homeowners paying a huge bill every month.

Financial return is another major incentive for going solar. Homeowners see various amounts of money they save, depending on a variety of factors, including:

  • Local electricity rates
  • Direct hours of daily sunlight
  • The size of your solar energy system
  • Electricity consumption
  • Whether your system is leased or owned
  • The size and angle of your roof

Anyone who is looking for a way to reduce their monthly utility bills and make a long-term investment that is low-risk should contact us at A-1 Guaranteed to have a solar energy system installed. Our own office bill is only about $24.00/month, even with all of our computers and people working!

Solar Energy Increases Your Home’s Value

Just about any type of upgrade increases a home’s value, and solar energy systems are no exception. Just like renovating your kitchen or finishing your basement, installing a solar energy system will attract premium buyers who are willing to pay top dollar. In one study, Lawrence Berkeley National Laboratory found that a solar energy system increases a home’s value by an average of $15,000! While various factors (as stated previously) can impact the size of the premium, on average, solar homes sell for more than homes without these systems.

Solar Energy Works Anywhere and is Environmentally Responsible

Most locations in the United States have good solar resource – even places such as Alaska and the Pacific Northwest. Just one hour of summer sun at noon is equivalent to the entire annual U.S. demand for electricity!

Each kilowatt-hour of solar power that is generated significantly reduces greenhouse gas emissions. These toxic emissions include sulfur oxides, carbon dioxide, nitrogen oxides, and particulates. In addition, solar power also reduces water consumption and withdrawal. Finally, the government provides tax breaks to solar energy system owners!

Contact us today for more information on having a new solar energy system installed, and let the savings begin!

Why Replacing – Not Repairing – Traditional Water Heaters is Now Recommended

Up until recently, property owners often had the choice of repairing or replacing their traditional water heaters when something went awry. Many would choose to repair them when possible, usually to save money.

However, that is no longer the recommended way to go.

Experts now recommend bypassing water heater repairs and just replacing them instead. The reason? The deadly risk of carbon monoxide poisoning. Carbon monoxide is a deadly gas that is colorless and odorless; it can be the byproduct of a malfunctioning furnace or water heater, most often.

Unfortunately, about 400 people die every year from unintentional carbon monoxide poisoning not linked to fires; over 20,000 people visit the emergency room, and more than 4,000 people annually are hospitalized because of it, according to the CDC.

When water heaters aren’t functioning properly, such as when they are leaking, they will keep running constantly to try to keep up with the water flow and demand. The carbon monoxide build-up that results is similar to running a car with the garage door closed for several hours.

How Carbon Monoxide is Dangerous

Carbon Monoxide poisons living things by preventing the body from receiving enough oxygen. As time goes on – and it usually doesn’t take long, depending on the severity of the leak – the body dies of asphyxiation.

When people breathe in carbon monoxide (CO) molecules, they attach to molecules that carry oxygen in the blood (hemoglobin). As the CO attaches more and more to hemoglobin, it prevents oxygen from being delivered to the body, killing cells.

Keeping Your Family Safe from CO Poisoning at Home

A-1 Guaranteed recommends that you do three things to prevent tragedy at the hands of this invisible, odorless gas:

  1. First and foremost, you must be sure that a carbon monoxide detector is installed in your home. It detects the dangerous gas well before it builds up to deadly levels that threaten lives. Place one near your water heater and one near your furnace, if you like, but have at least one in the vicinity of these systems.
  2. Pay attention to your water heater. Is it taking far too long for it to heat up water? Is it running more often than it should? Do you see any leaks, breaks in pipes, or anything else out of sorts? If so, or if you’re not sure, contact us right away.
  3. Make regular inspections of your water heater. You can detect small issues before they become big problems, and can make sure that everything is working safely and properly. Should your water heater found to not be safely or properly functioning, we’ll help you replace it with a new one right away. You may want to consider a tankless water heater for eco-friendly operation and money savings.

A little diligence goes a long way when it comes to water heaters, and when the stakes are so high, no one can afford to risk carbon monoxide poisoning at the hands of a faulty system. Contact A-1 Contact Contact A-1 Guaranteed today and schedule an appointment to replace your water heater as soon as possible to avoid a devastating tragedy.

unfortunately we don’t work on water heaters unless they are our installation.  We only replace them so we would not be able to inspect one in their home

When Should You Consider Replacing Your Home HVAC Ductwork?

It’s common knowledge that furnaces and air conditioners don’t last forever, and need to be replaced every 15 or so years. However, what many homeowners don’t realize is that their ductwork isn’t indestructible either, and must also be replaced. These ducts are essential to maintaining proper ventilation and air filtration in the home. Although they are often forgotten (usually because of their hidden placement) they need attention, maintenance and sometimes, replacement.

How do you know when it’s time to replace your HVAC system’s ductwork? Following are the biggest signs to look for that will let you know:

1. Inadequate Airflow

Airflow is the essential component of an efficient HVAC system. If you notice that the air flowing out of your vents and registers isn’t as strong as it used to be, it may be time for replacement. When your ductwork is old, dirty, clogged, or has holes in it, your home performance will suffer the consequences – and so will your wallet.

2. Age

Air ducts typically last for about 10-15 years with proper care. Over time, however, duct seals, seams, and joints are susceptible to deteriorating, especially if they are subjected to humid conditions much of the time. Some of the consequences of old, compromised ducts include overuse of energy, rising heating and cooling bills, poor performance, and an uncomfortable home.

3. Odors and/or Mold

Mold is a severe issue in homes when it gets out of control, and this is especially true when it gets into your ductwork. Every time your furnace or air conditioner kicks on, it spreads odors and mold spores throughout your house. Intense allergies, headaches, and serious long-term health effects can be caused by unseen mold and poor air quality. Contact A-1 Guaranteed right away if you notice foul odors or spot mold in your vents, registers, or ductwork.

4. Noisy Operation

Ductwork is designed to be silent as it does its job, so if you notice strange sounds coming from your air ducts, it could signal problems like unseen damage, clogs, or leaks. Although issues like these may not be visible, it’s a good indication that there is a problem somewhere. If your ductwork system makes odd noises as air flows through it, the issue should be addressed by one of our technicians and diagnosed for repair or replacement.

5. Improper Design or Installation

Every home deserves an HVAC system that is properly installed and strategically designed for optimal performance when heating and cooling. Far too many homes have ducts that really are “all over the place”, often due to previous alterations by one homeowner or another. Improper design or installation is one of the biggest (and most expensive) causes of residential energy loss in the country. Even if you have a brand new air conditioner or furnace installed, if your ductwork isn’t properly installed or the layout is subpar, you’re going to pay dearly for it. If you notice hot spots and cold spots around your home, it’s a good bet that you’re losing energy and paying a fortune for it.

6. Pests and Rodent Damage

Unfortunately, there are many critters that may get in your ductwork, including rodents. They may chew through the ductwork and even urinate on and in them. Be sure to contact a pest control service, and once your guests are no longer living in your home, you may need to replace your ductwork.


A-1 Guaranteed can diagnose and remedy your ductwork issues, from moldy ducts to broken seams to cold spots and poor airflow. We can replace any ducts that are beyond repair – even if you need every duct in your home replaced. Whether you know where the issue lies already or you just have a feeling something isn’t right somewhere, let our expert technicians get your home back to having the comfortable, clean air flow and air quality you deserve. Contact us today.

Can You Still Get HVAC, Air Quality, and Water Heater Service During the COVID-19 Pandemic? YES!

To say that the 2020 COVID-19 pandemic has turned the country upside down is an understatement, especially in California. From L.A. to Fairfield to Hollywood, residents and businesses have had to upend everything and operate on unfamiliar ground for months.

While many businesses have sadly had to close their doors and some services are no longer available for the time being, there are still many essential appointments that can still be made – and HVAC is one of those! A-1 Guaranteed has had to change the way we provide our essential service, but we’re here to help our customers in every way possible now, just as we always have.

What HVAC Services Can We Still Provide?

Our team is available to provide our customers in Napa, Solano, Contra Costa, and the surrounding areas with heating, air conditioning, tankless water heater, solar, and air quality services. Should your furnace act up or go out, give us a call for quick, professional service. We can still diagnose and fix air conditioners and furnaces, set you up with a new tankless water heater, install solar energy, remedy serious home performance issues, and help improve the quality of air in your home, for example.

Are There Any Services that are not Available at this Time?

Unfortunately, we are not able to perform some services such as minor installations of things like bathroom fans or kitchen vents, as they are not considered essential.

What Steps Do We Take to Ensure Our Customers’ and Employees’ Safety?

We take the health and safety of our technicians and customers very seriously here at A-1 Guaranteed. Therefore, we request that our customers let us know if anyone in the home has been sick with COVID-19 or has been exposed to the coronavirus. When our technicians do visit your home for your appointment, they will enforce social distancing. In addition, they must have a sink available to them so they can wash their hands regularly. Finally, every technician will don shoe covers, gloves, and masks not just for their safety, but for the safety of our customers, as well.

Trust A-1 Guaranteed for Safe, Prompt HVAC Service in the Bay Area

Although our office is closed to walk-in customers, our staff is always available via email and phone. We are still ready to provide you with emergency services as well as repair and installation services for your solar energy system, air quality system, HVAC, water heater, and more. Contact us today and let us know how we can help you.

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