FAQ

Need step-by-step help? See our how-to guides.

How It Works

What is a heat pump water heater?

A heat pump water heater uses electricity to power the heat pump to move heat from the ambient air into the water. Depending on conditions, they operate at 200% to 500% efficiency, which means that between two and five units of heat go into the water for every unit of electricity that is used. Traditional water heaters are only around 60% to 93% efficient (gas, electric respectively) depending on type. That’s a big difference, and results in substantial reductions in energy use and CO2 emissions while saving you money.

Note: Heat pumps sometimes use the term Coefficient of Performance, or COP, instead of efficiency. It is a ratio of how much heat energy into the water vs. how much energy is consumed.

What makes Cala different from other heat pump water heaters?

Cala heats water with Cala Predictive Intelligence™ - learning your home’s unique hot water habits and adjusting automatically. Cala saves energy, lowers your bills, and ensures you always have hot water without programming modes or temperatures like other heaters require. Cala is the only water heater that can autonomously adjust tank temperature based on predicted demand to make sure hot water is available when you need it.

When connected to Wi-Fi and paired with the Cala app, Cala Predictive Intelligence™ gets even smarter. It combines flow sensor readings with live data streams - like electricity pricing, solar forecasts, and CO₂ emissions - to decide when, how fast, and to what temperature your water should be heated. The result: maximum savings, comfort, and a smaller carbon footprint.

No other water heater has Cala Predictive Intelligence™.

Does Cala save money by lowering the hot water temperature?

No. Cala’s #1 job is to ensure ample hot water is available, but do so as efficiently and cost effectively as possible based on the demand in your home.

Does Cala require an internet connection to work?

No. Cala is designed to operate without an internet connection—this is a core part of the system. You will always have hot water.

Even offline, Cala continues to function as an intelligent heat pump water heater using predictive control. All hot water usage data is stored locally on the unit.

That said, connecting Cala to Wi-Fi unlocks its full capabilities. With an internet connection, you can:
- Access the mobile app for remote monitoring and control
- Enable features like Solar Sync and time-of-use optimization
- Receive secure over-the-air (OTA) software updates that improve performance over time

For example, when Solar Sync is enabled, Cala downloads a solar production forecast for your home and uses it to optimize heating through its Model Predictive Control system.

Without Wi-Fi, Cala will still deliver reliable hot water—but you won’t have access to these enhanced features and ongoing improvements.

How do Cala Intelligence Preferences work?

Cala Intelligent Preferences are optional features available in the Cala app providing advanced customization for your home. Once you configure these settings, Cala Predictive Intelligence™ will incorporate them into its water heating plan for your home. See Using the app in our how-to guides.

Does Cala work with a recirculation pump?

Yes, Cala works with recirculation systems as long as the installation configuration and pump programming follow our guidelines - learn more here. See Tell Cala about your recirculation pump.

How do I connect Cala to Home Assistant?

Follow our Home Assistant guide for step-by-step setup instructions.

Installation

I have an electric water heater now. What will installing Cala involve for me?

The plumbing and power connections from your existing electric water heater will be reused, which simplifies the installation. A condensate line will be installed to carry away water that Cala removes from the air during operation - similar to how an air conditioner drips in the summer. This is a standard plumbing operation with a line that is either routed to a nearby drain or to a condensate pump.

If your Cala unit is going to be installed in a space less than 700 cubic feet (multiply the length x width x height of your room to find the cubic feet), then other airflow considerations must be taken into account like having louvered doors, and/or ducting the unit.In this situation, your Cala Pro Contractor, or your preferred installer, will assess your home prior to installation.

I have a natural gas, oil or propane water heater now. What will installing Cala involve for me?

You will likely need to install a new 240v/30 amp circuit to the location of your water heater. This is straightforward in most – but not all – homes. Where there are challenges, professional installers are usually able to overcome them. Your Cala Pro Contractor, or your preferred installer, will assess your home prior to installation. Next, a condensate line will be installed to carry away water that Cala removes from the air during operation.

Installing a condensate line is a standard plumbing operation with a line that is either routed to a nearby drain or to a condensate pump. If your Cala unit is going to be installed in a space less than 700 cubic feet (multiply the length x width x height of your room to find the cubic feet), then the air inlets and outlets will need to be ducted to a separate space or a louvered door will be installed. In this situation, your Cala Pro Contractor, or your preferred installer, will assess your home prior to installation.

How much space do I need?

Cala will need 34 inches x 34 inches of available floor space and 77 inches of ceiling height. Cala should be placed in a room with at least 700 cubic feet of air (Length x width x height of room). If the room is less than 700 cubic feet your Cala unit may need to be ducted or installed with louvered doors - The Cala team or your installer can help you with the best solution here.

What are the electrical requirements for installation?

Cala requires a 30 amp, 240V circuit. This is typical of most electric water heaters and if you are replacing an electric or heat pump water heater the existing circuit will most likely work. If you are replacing a natural gas, propane, or oil water heater a new electrical circuit may need to be installed.

I’ve read that heat pump water heaters make noise and blow cold air, is that true?

When your Cala is heating it makes about the same noise as a dehumidifier, refrigerator or dishwasher, but you’re unlikely to hear this unless you’re nearby. It will also blow cool, dehumidified air while it’s running. See Set quiet hours.

Is there a ducting kit available?

We have ducting kits for both the air inlet and air outlet although most homes don’t need one. Your Cala Pro Contractor can help you determine if you need one, or you can refer to our Owner’s Guide when it becomes available.

What’s involved with installation?

Your current water heater will be drained and removed and disposed of, then your Cala water heater will be put in its place. Plumbing and electrical connections will be made to your Cala unit and a condensate drainage line will be installed. If you’re replacing a natural gas, oil or propane water heater then installation will usually include the addition of a new 240V circuit and the natural gas, propane or oil lines will be capped.

If your Cala unit is being installed in a closet or small space, it may be ducted to a larger space or the door may be changed. Most water heater installations take less than one day.

How do I know if there is a Cala Pro Contractor in my area?

Enter your ZIP code on our Find a Pro page to see if your area is covered.

If we don’t yet have a partner in your region when your unit becomes available, you’ll have the option to hire your own installer, install it yourself, or wait until a Cala Pro Contractor is available.

Are Cala Pro Contractor licensed?

Yes. All Cala Pro Contractor have been vetted by our team and are required to be licensed and insured.

If I want to use my own installer, will they need training?

They do not need to attend a formal training, but we do give them plenty of resources if they have any questions. They will be able to download our installation guide and we also offer installer support via phone and email. Cala’s installation is the same as other heat pump water heaters.

How will my Cala water heater come to my house?

If you choose to have your Cala water heater installed by a Cala Pro Contractor, we’ll ship it to them and they’ll deliver it to your home. If you choose to install through your own installer or install it yourself, we’ll deliver it to you. Depending on your location, shipping and handling costs may apply.

Do I need a building permit to install a Cala water heater?

Permitting requirements vary by jurisdiction, but it’s standard practice for installers to be familiar with the requirements for their service territories. We recommend discussing permitting requirements with your installer (Cala’s or your own), or contacting your local government if you plan to install it yourself.

Does Cala require a subscription?

There are NO subscriptions or fees required after installation. Our app is free to download for both iOS and Android.

How do I know if Cala is the right size for my home?

Today, Cala is available in a 65-gallon model.

For most households of up to about 5 people, this is a good fit. Cala also increases effective hot water capacity using an integrated mixing valve and predictive controls, so it can deliver more usable hot water than a standard tank of the same size.

For larger households or very high hot water usage, we’re actively working on an 80 gallon model that will be available in the future.

If you’re unsure, we’re happy to help assess your home and usage to make sure it’s a good fit.

Can Cala be installed in a closet or small space?

In many cases, yes—but it depends on the space.

Cala requires:
- About 34” x 34” of floor space
- 77” of height
- Access to enough air (typically 700 cubic feet)

If the space is smaller—like a closet—solutions such as louvered doors or ducting can often make installation possible.
‍
The best next step is to have an installer review your setup. They can confirm what’s needed and recommend the right approach for your home.

What sizes are available?

Today, Cala is available in a 65-gallon model.

For most households of up to about 4–5 people, this is a good fit. Cala can also deliver more usable hot water than a standard tank of the same size thanks to its mixing valve and predictive controls.

We’re actively working on additional sizes, including a larger model designed for higher-demand households. These will be available in the future.

Can Cala be used for radiant floor heating or hydronic systems?

No. Cala is designed to provide domestic hot water (showers, sinks, appliances), not space heating.

If your current system uses a boiler for radiant floors or radiators, that heating system would remain separate. Cala can replace the hot water portion of your setup, but it does not power hydronic heating.

Costs & Savings

Why does Cala have a flow sensor?

By measuring your home’s hot water habits, Cala is able to more accurately predict your future hot water use to deliver the right amount of hot water while saving you money. See Your first month: how Cala learns.

Why is a variable speed compressor useful in a heat pump water heater?

Unlike most traditional heat pump water heaters whose compressors run at one speed only, our variable speed compressor can operate at a range of speeds. This means your Cala can heat more slowly - which is up to 20% more efficient and saves you money - or heat more quickly, delivering you faster recovery. Cala is the first water heater to combine a variable speed compressor’s benefits with advanced controls.

What is a mixing valve and why does Cala have one?

The mixing valve senses the water temperature at the tank outlet and adds in cold water if the hot water is above the temperature setpoint on the valve. This enables Cala to heat the water in the tank above the delivery temperature and increase the effective capacity of the tank when it’s beneficial, like before periods of high hot water use, prior to a potential power outage, or during periods of low electricity prices.

Mixing valves have been used for decades and some jurisdictions require them to be installed on all water heaters. See Adjust the water temperature at your taps.

How do Cala’s advanced controls work?

Other water heaters heat only based on the temperature in the tank at that moment. Cala considers information like your expected hot water demand over the next few hours, your electricity pricing, and more – meaning it’s better able to ensure hot water is available while saving you money, and coordinating its heating with your personal preferences.

What rebates and tax incentives are available to me?

Cala is eligible for many state and utility rebate programs, though availability and amounts depend on your location and electric utility. Rebate programs vary by region and may change over time, but in some areas, incentives can significantly reduce the cost of installing a heat pump water heater.

To explore your local options, use our rebate finder.

Does Cala qualify for rebates in California?

Cala may qualify for certain incentives tied to ENERGY STAR certification, depending on your utility. However, it is not yet tested to the NEEA Advanced Water Heating Specification, so some rebates may not be available. Since eligibility varies, we recommend confirming details directly with your local utility.

Will my savings be like the examples?

Your savings will vary based on several factors, including your household’s hot water use, local energy prices, location, and installation costs. Please reach out to us at info@calasystems.com if you’d like a personalized estimate.

What is the warranty?

We offer a comprehensive 10-year warranty designed to provide peace of mind for you and your customers. Product support is available directly from Cala representatives.

Labor is covered for 1 year. This extends to 3 years when the system is installed by a Cala Pro contractor. If you choose to work with your own installer, please contact Cala to ensure they are registered with us so you can qualify for the 3-year labor warranty.

Read our full warranty here.

What is your Qualified Manufacturer Identification Number?

Our Qualified Manufacturer Identification Number is G6R5.

Do I need solar for Cala to be worth it?

No—solar is not required.

Cala is designed to be highly efficient on its own, even without solar. You’ll still benefit from lower energy use and reduced operating costs compared to a standard electric water heater.

If you do have solar, Cala can take it a step further by heating water when your system is producing the most energy. But even without solar, Cala remains a strong upgrade from traditional systems.

What material is the water tank made of?

Cala uses a glass-lined carbon steel tank—the industry standard for durable water heaters. The glass lining protects against corrosion, and an internal anode rod helps extend the life of the tank over time.

become a cala pro contractor

As a Professional Contractor, do I buy Cala directly from you?

Yes, we ship directly to our installation partners. We accept major credit cards and ACH.

How does Cala installation compare to other water heaters?

We consulted plumbers and contractors from all over the US during development to ensure our installation is as straightforward as possible. Like other heat pump water heaters, Cala’s installation is similar to installing an electric water heater, with the addition of a condensate line. If the unit is being installed in a closet or small space, it may have to be ducted to a larger space or the door may be changed. Once installed, you’ll simply follow the intuitive prompts on your Cala to get it running.

When will Cala be available to me?

Cala now ships nationwide, with the exception of Hawaii, Washington, Oregon, and Alaska.

To check if a Cala Pro installer is available in your area, visit our Find a Pro tool

If a Cala Pro isn’t available yet, you can still purchase Cala and work with your own contractor—we’re happy to support them through the installation.

We continue to expand our network of Cala Pro partners, so availability will keep improving over time.

Payment and Reservation

How do I pay for my Cala?

If you purchase Cala directly, you can check out through our online store using any major credit card. If you work with a Cala Pro Contractor, you’ll buy both your Cala unit and installation directly from them.

When will Cala be available in my region?

Cala is currently shipping in select regions, with new shipping areas and Cala Pro contractors added regularly.

The easiest way to check availability in your area is to click Shop Now and enter your ZIP code. You’ll immediately see whether we ship to you. If we’re not in your region yet, you can join our list and we’ll notify you as soon as availability expands. Contractors interested in becoming a Cala Pro can also reach out to start the process.

Is my reservation payment refundable?

Yes. Your reservation payment is 100% refundable.

How It Works

Will Cala Fit?

Savings

CALA vs OTHERS

Tech & Specs

Frequently Asked Questions

Frequently Asked Questions