Top tankless water heater features for pros and customers

Today’s tankless water heaters are loaded with heavy-duty tech — like internal recirculation pumps, built-in scale prevention, WiFi, freeze protection, condensing heat exchangers, and smart flow controls — built to boost efficiency, cut down on callbacks, and make your installations a whole lot easier.

As manufacturers continue to innovate, understanding which tankless water heater features provide the greatest value can help you select the right solution for each application. Factors such as water quality, climate, home size, and homeowner expectations all play a role.

Scale prevention features

Mineral buildup is one of the most common causes of reduced performance and maintenance issues in a tankless water heater. To address this challenge, many manufacturers now offer integrated tankless water heater scale prevention technologies, maintenance reminders, and advanced heat exchanger designs. Many premium units utilize a stainless steel or copper heat exchanger design to improve durability and heat transfer while helping maintain performance over time.

While scale prevention features can help reduce buildup, regular maintenance remains important for long-term performance. For contractors, these systems can also create opportunities to offer ongoing maintenance services, such as annual descaling and system inspections, helping homeowners protect their investment while supporting long-term customer relationships.

Consider scale prevention when:

• Installing in hard water regions

• Customers want to minimize maintenance requirements

• The unit will experience heavy daily usage

• Long-term efficiency and equipment lifespan are priorities

Internal recirculation and instant hot water

One of the most requested tankless water heater features is faster hot water delivery. Many modern systems include a built-in tankless water heater recirculation pump or intelligent recirculation technology that can reduce wait times at fixtures. Some manufacturers, such as Rinnai, offer proprietary solutions such as Smart Circ® Intelligent Recirculation systems that learn household usage patterns to optimize comfort and efficiency.

For larger homes, a tankless water heater buffer tank may also help improve performance and reduce cycling.

Consider internal recirculation when:

• The home has long plumbing runs

• Homeowners want an instant hot water tankless water heater experience

• Water conservation is important

• A simplified installation is preferred

Smart Water Heater Controls

A growing number of homeowners are looking for convenient, connected home solutions, and today's WiFi tankless water heater models offer advanced monitoring and control capabilities that provide that. Some systems utilize Bluetooth water heater connectivity or accessories such as the Rinnai Control-R Module to provide remote access and enhanced serviceability. Smart controls often allow the ability to remotely adjust water temperatures, receive maintenance notifications and diagnostic alerts, monitor usage, and manage system settings through a mobile app, offering greater convenience and visibility into system performance.

Smart controls can also boost troubleshooting efficiency. Remote monitoring capabilities may allow technicians to review diagnostic information and error codes before arriving on-site, helping ensure the correct replacement parts are available and reducing the potential for additional service trips.

Consider smart features when:

• Homeowners want greater control over system operation

• Remote monitoring is desirable

• Serviceability is a priority

• The home includes other smart technologies

Advanced diagnostic tools and flow management

Many manufacturers now incorporate advanced flow control technologies and onboard diagnostics that help maintain consistent water temperatures while simplifying troubleshooting. Depending on the model, these features may include self-diagnostic software, maintenance reminders, error-code reporting, performance monitoring, and advanced flow control systems that automatically respond to changes in demand.

Consider advanced diagnostics when:

• Easy servicing is important

• The installation location is difficult to access

• Reducing troubleshooting time is a priority

• Customers value proactive maintenance information

Flexible venting options

Venting requirements can significantly impact tankless water heater selection. Some models offer expanded venting lengths, multiple venting materials, and installation flexibility that simplify retrofit projects. Manufacturers may offer specialized venting systems, such as Rinnai® Versa Vent technology, that allow greater installation flexibility in certain applications.

Features such as built-in crossover valves, top-mount connections and support for 2-inch PVC venting can also help streamline installations by reducing the amount of drilling, piping and rework required on the job site. These time-saving features can translate into faster installations, lower labor costs and the ability to complete more jobs throughout the week.

Consider flexible venting when:

• Retrofitting an existing home

• Space is limited

• Venting pathways are complex

• Installation constraints affect equipment placement

High-efficiency operation and condensing technology

Many homeowners choose a condensing tankless water heater because of its superior efficiency and lower operating costs. Condensing systems capture additional heat from exhaust gases before they exit the venting system, improving overall efficiency. Many high-performance models also utilize dual stainless steel heat exchangers to maximize energy recovery. Advanced burner designs such as ultra low NOx tankless water heater models can also help reduce emissions while maintaining high performance.

Consider a condensing tankless water heater when:

• Energy savings are a primary goal

• Utility costs are a concern

• Hot water demand varies throughout the day

• Long-term operating savings are desired

Freeze protection and cold climate performance

Some tankless water heaters include built-in tankless water heater freeze protection systems to help protect internal components in cold weather. For mountain communities, a high-altitude tankless water heater is sometimes necessary to maintain performance at the more extreme elevation.

Consider freeze protection when:

• Installing in colder climates

• The unit will be in an unconditioned space

• Outdoor installation is being considered

• Seasonal temperature fluctuations are common

Commercial applications and cascading systems

Larger homes and commercial installations often require greater hot water capacity. In these situations, a water heater cascade configuration can connect multiple units together to meet peak demand. By staging units on and off based on real-time hot water usage, cascading systems can increase capacity while improving energy efficiency, reducing wear on individual units, and providing built-in redundancy if one water heater requires service.

Top tankless water heater features

By understanding features such as condensing technology, advanced flow control, WiFi connectivity, freeze protection, water heater cascade systems, and scale management technologies, contractors can make more informed recommendations while helping homeowners maximize performance, efficiency, and comfort.

Ferguson helps you stay ahead of the latest tankless water heater innovations with access to leading brands, expert support, and the products needed for virtually any application. Shop with Ferguson today to find the right solution for your next installation.