Outdoor Tankless Hot Water Heater Reviews

Outdoor Tankless Hot Water Heater Reviews: A Comprehensive Guide

Outdoor tankless hot water heaters represent a significant advancement in water heating technology, offering on-demand hot water and space-saving benefits compared to traditional tank-based systems. These units are designed to be installed outside the home, freeing up valuable indoor space and simplifying ventilation requirements. This article provides a comprehensive overview of outdoor tankless hot water heaters, covering key considerations, performance characteristics, popular models, and factors to consider when making a purchasing decision.

Tankless water heaters, also known as on-demand water heaters, heat water only when needed. When a hot water tap is turned on, cold water travels through a pipe into the unit. A flow sensor detects the water flow and activates a high-powered burner, which heats the water as it passes through a heat exchanger. The heated water is then delivered to the faucet or appliance. When the demand for hot water ceases, the burner shuts off, ending the heating process. This on-demand operation eliminates the standby heat loss associated with traditional tank water heaters, where water is constantly heated and stored, even when not in use.

The outdoor configuration of these tankless systems offers several advantages. Principal among these is the elimination of the need for potentially complex indoor venting systems. Indoor tankless heaters require specialized venting to safely exhaust combustion gases, which can add to the overall installation cost and complexity. Outdoor units, by contrast, vent directly into the atmosphere, simplifying the installation process and reducing associated expenses. Furthermore, outdoor installation frees up valuable interior space, which is often a significant consideration, particularly in smaller homes or apartments.

Key Considerations When Choosing an Outdoor Tankless Heater

Selecting the appropriate outdoor tankless water heater requires careful consideration of several factors to ensure optimal performance and longevity. These include evaluating hot water demand, considering climate conditions, assessing fuel type options, and examining the unit's energy efficiency and safety features.

Hot Water Demand: The first step in selecting an outdoor tankless water heater is to accurately assess the household's hot water demand. This involves determining the number of simultaneous hot water applications that are likely to occur. For example, a family might simultaneously use a shower, a dishwasher, and a washing machine. Each appliance and fixture has a specific flow rate, typically measured in gallons per minute (GPM). To determine the peak demand, the flow rates of all simultaneously used appliances and fixtures should be added together. The tankless water heater must have a GPM rating that meets or exceeds this peak demand to ensure an adequate supply of hot water. Overestimating the demand can lead to unnecessary expenditure on a larger unit, while underestimating it can result in insufficient hot water during peak usage times.

Climate Conditions: The climate in which the outdoor tankless water heater will be installed plays a significant role in its performance. In colder climates, the incoming water temperature is significantly lower, which means the unit must work harder to raise the water temperature to the desired level. This can impact the unit's GPM rating, as it may not be able to deliver the same flow rate at a specific temperature rise in colder conditions as it can in warmer climates. Consequently, it is crucial to select a unit with sufficient heating capacity to compensate for the lower incoming water temperature. Some manufacturers offer models specifically designed for colder climates, with increased BTU (British Thermal Unit) ratings to provide adequate hot water even in freezing temperatures. Additionally, measures should be taken to protect the unit from freezing, such as insulating exposed pipes or using a freeze protection kit, which typically involves circulating warm water through the unit during freezing temperatures.

Fuel Type Options: Outdoor tankless water heaters typically operate on either natural gas or propane. The choice between these fuel types often depends on the availability of a natural gas line at the installation location. Natural gas is generally less expensive than propane, but the cost of running a new gas line to the unit can offset this savings. Propane offers more flexibility in terms of installation location, as it can be supplied by portable tanks. However, propane tanks require regular refilling, which can be inconvenient and add to the overall cost. The BTU rating of the unit should also be considered, as it directly impacts the unit's heating capacity. Higher BTU ratings are generally required for households with higher hot water demand or for installations in colder climates.

Energy Efficiency and Safety Features: The energy efficiency of an outdoor tankless water heater is a crucial consideration for long-term cost savings. The Energy Factor (EF) rating is a measure of the unit's overall efficiency, with higher EF ratings indicating greater energy savings. Tankless water heaters generally have higher EF ratings than traditional tank-based systems due to their on-demand operation. Look for models with advanced features such as modulating burners, which adjust the heating output based on the actual hot water demand, further improving efficiency. Safety features are also paramount. These include overheat protection, which shuts off the unit if it gets too hot, and freeze protection, which prevents damage from freezing temperatures. Models with electronic ignition systems are generally safer and more reliable than those with pilot lights.

Popular Outdoor Tankless Water Heater Models

Several manufacturers offer outdoor tankless water heaters with varying features and performance characteristics. Researching and comparing different models is essential to select the unit that best meets the specific needs and budget of the user.

Rinnai RUR199iN: Rinnai is a well-known brand in the water heating industry, and the RUR199iN is a popular outdoor model known for its high efficiency and performance. It boasts a maximum flow rate of up to 11 GPM, making it suitable for larger households with multiple hot water demands. This unit features a modulating burner that adjusts the heating output based on the actual demand, optimizing energy efficiency. It also incorporates advanced safety features, including overheat protection and freeze protection. The RUR199iN is compatible with both natural gas and propane, offering installation flexibility. Its compact design and outdoor-rated construction make it an ideal choice for space-saving and simplified installation.

Navien NPE-240A2: Navien is another leading manufacturer of tankless water heaters, and the NPE-240A2 is a highly efficient outdoor model designed for reliable performance in various climates. It features a high-efficiency condensing design that maximizes heat transfer and minimizes energy waste. The NPE-240A2 offers a maximum flow rate of up to 11.2 GPM, making it suitable for larger homes. It also incorporates a recirculation system that provides hot water on demand, reducing water waste and improving convenience. This unit is compatible with both natural gas and propane and features advanced safety features, including overheat protection and freeze protection. Its durable construction and outdoor-rated design ensure long-lasting performance.

Takagi T-H3M-DV-N: Takagi is a reputable brand known for producing reliable and durable tankless water heaters. The T-H3M-DV-N is an outdoor model designed for medium-sized households. It delivers a maximum flow rate of up to 8 GPM, which is sufficient for most typical household needs. This unit features a modulating burner that adjusts the heating output based on the demand, optimizing energy efficiency. It also incorporates built-in freeze protection, making it suitable for colder climates. The T-H3M-DV-N is compatible with natural gas and features a compact design that simplifies installation. Its durable construction and outdoor-rated design ensure reliable performance for years to come.

Installation and Maintenance Considerations

Proper installation and regular maintenance are essential for ensuring the optimal performance and longevity of an outdoor tankless water heater. Installation should always be performed by a qualified professional to ensure compliance with local codes and regulations. Incorrect installation can lead to safety hazards and void the manufacturer's warranty.

Installation: During installation, the unit should be securely mounted on a stable surface, ensuring adequate clearance for ventilation and access for maintenance. The gas and water connections should be properly sealed to prevent leaks. The venting system, if required, should be installed according to the manufacturer's instructions and local codes. It is also important to ensure that the unit is properly grounded to prevent electrical hazards. Depending on local regulations, permits may be required before installing a tankless water heater. It is advisable to consult with a local building inspector to determine the specific requirements in the area.

Maintenance: Regular maintenance is crucial for maintaining the efficiency and extending the lifespan of the tankless water heater. The frequency of maintenance depends on the water quality in the area. Hard water, which contains high levels of minerals such as calcium and magnesium, can lead to scale buildup inside the unit, reducing its efficiency and potentially causing damage. Descaling the unit regularly, typically once a year, is essential in areas with hard water. This involves flushing the unit with a descaling solution to remove mineral deposits. It is also important to inspect the unit regularly for leaks, corrosion, and other signs of damage. The air filter should be cleaned or replaced periodically to ensure proper airflow. Consulting the manufacturer's instructions for specific maintenance recommendations is highly recommended.

Troubleshooting: Even with proper installation and maintenance, issues can occasionally arise with tankless water heaters. Common problems include insufficient hot water, fluctuating water temperatures, and error codes. Many of these issues can be resolved with simple troubleshooting steps. For example, insufficient hot water may be caused by a clogged water filter or a gas supply problem. Fluctuating water temperatures may be due to low gas pressure or a faulty flow sensor. Error codes typically indicate a specific problem with the unit, and the manufacturer's manual should be consulted for troubleshooting information. If the problem cannot be resolved through troubleshooting, it is essential to contact a qualified technician for assistance.