Stiebel Eltron Tempra 29 Plus Tankless Water Heater Review

The Stiebel Eltron Tempra 29 Plus suits small to medium sized homes that want steady hot water without a bulky tank. Its no-vent design fits most utility areas and supports households that run several fixtures during peak times. The system heats water as it flows, which helps prevent long waits and keeps things simple for everyday use.

The Tempra 29 Plus has become a common choice among homeowners upgrading to an electric tankless unit. Many buyers pick it for its stable output, whisper-quiet operation, and good record of reliable performance in cold climates. The model often shows up in consumer discussions as a dependable option for families that want consistent hot water on-demand.

Key Features

• Advanced Flow Control
• Digital LED Display
• Two Memory Presets
• Self-Modulating System
• 99% Efficiency
• 28.8 kW Power
• Frost Protection

Technology and How It Works

Tankless systems heat water only when a tap opens. The Tempra 29 Plus follows this method. Cold water passes through heating chambers that raise the temperature to the level you select. This on-demand approach avoids the heat loss that comes with storing water in a tank. It also removes recovery time since there is no reservoir to refill or reheat.

The Advanced Flow Control technology it uses is an industry-exclusive feature found in Stiebel Eltron Plus models. This system manages output when demand gets high. When several fixtures run at once and flow rises past what the heater can warm to the set point, the unit lowers the water flow slightly to keep the temperature steady. The adjustment is automatic. The aim is to reduce sudden temperature changes and keep showers comfortable.

A quick comparison with a tank heater helps show the benefit. A tank model uses a stored supply, which runs out once the tank empties. The Tempra 29 Plus heats water as it moves through the unit, so the supply continues as long as demand stays within its limits. This difference helps during busy times, such as morning routines with showers and sinks in use.

Flow rate depends on the temperature of the incoming water. Warmer water needs less heating, which allows a higher output.

Typical maximum flow rates for a 105°F setting include:

• 3.0 GPM at a 40°F inlet
• 3.6 GPM at a 50°F inlet
• 4.4 GPM at a 60°F inlet
• 5.6 GPM at a 70°F inlet

The unit also adjusts power use based on demand. A single tap draws less energy than several fixtures running at the same time. This helps the system manage output and maintain steady performance without extra effort from the homeowner.

Performance and Heating Capability

The Tempra 29 Plus performs well in everyday use, especially in homes located in colder regions. Groundwater in these areas often enters at lower temperatures, so the system works harder to bring water up to a typical 105°F setting. Even with the extra load, it maintains steady output as long as the total demand stays within the unit’s limits.

In a typical home, the heater can support two to four fixtures at once. How many you can use depends on the incoming water temperature and the flow rate of each fixture. Most showerheads and faucets run between 1.5 and 2.5 gallons per minute, which gives you a good idea of how much the heater can handle during busy times.

Real-world use is usually the best way to understand its capability. Common combinations such as a shower and a kitchen sink work without any temperature swings. A shower paired with a dishwasher cycle also stays stable under most conditions. When more than two high-flow fixtures open at the same time, the heater adjusts as needed to protect temperature consistency.

The unit responds quickly when fixtures start or stop. This helps prevent brief cold spots and keeps water comfortable as household activity changes. In colder climates, each fixture has a smaller buffer before flow limits are reached, but most daily routines stay well within the system’s capacity.

Controls and User Experience

The Tempra 29 Plus is easy to operate thanks to its crystal clear LED display and simple dial selector. The large dial makes it straightforward to adjust the output temperature anywhere from 68°F to 140°F, and the system responds quickly to small changes.

The display shows the active temperature setting in either Fahrenheit or Celsius, along with a power capacity bar that indicates how much of the unit’s heating capability is being used at the moment. It also shows the current flow rate in gallons per minute or liters per minute, which helps you understand how the system is performing while in use.

Below the display are three buttons:

• Information button
• Preset 1 button
• Preset 2 button

The two presets let you store preferred temperatures so you can switch between them without needing to re-adjust the dial each time. This is helpful for instances such as if you want a bath at a certain water temperature or when moving between tasks.

Although the unit does not include lock features, it has built-in safeguards that support safe operation without adding complexity for the user. These include thermal cut-out switches, frost protection, and automatic shutdown if unsafe temperatures or abnormal conditions are detected. These protections work in the background, so the controls stay simple while the system manages safety on its own.

Energy Efficiency and Operating Costs

Energy use depends on how long the heater runs and at what fraction of its maximum output. Use this simple formula to estimate consumption: kWh = kW × hours.

Full output is about 28.8 kW, so one hour of continuous full-load operation equals 28.8 kWh. Half that output for one hour equals 14.4 kWh. A 30-minute continuous full-load run uses about 14.4 kWh.

If the unit runs at half power for ten minutes, it uses approx. 2.4 kWh. Running near full power for thirty minutes uses about 14.4 kWh. Multiply the kWh result by your local electricity price to get cost. For instance, 2.4 kWh at 0.25 per kWh costs 0.60.

Cold incoming water increases runtime and raises total kWh for a given hot-water task. The heater’s self-modulation helps limit wasted power, but the final energy use still depends on how often and how long hot water is needed and on local electricity rates.

Installation and Setup

The Tempra 29 Plus requires installation by licensed professionals. Stiebel recommends hiring a qualified electrician and plumber to handle the work due to the electrical load and the need for proper plumbing connections. Professional installation also protects the warranty and reduces the risk of issues that come from incorrect wiring or improper water line setup.

Electricians first check that the home can support the load. This model needs three double pole 40 amp breakers and 8 gauge wire to manage its 120 amp draw. The installer reviews the service panel and makes upgrades if needed. These steps stay in the background for the homeowner, but they matter because the heater only works at full capability when it receives stable power.

Plumbers focus on the water side of the setup. The unit uses 3/4 inch connections located at the bottom, and installers make sure these fittings are aligned without strain. Hot water outlet pipes often reach high temperatures, so insulation is recommended. This helps reduce heat loss in colder climates and keeps exposed pipes safer to touch. The installer also checks for steady pressure and confirms that the flow matches the requirements of the heater.

Cold climate installation brings a few added considerations. The unit needs to stay in a frost free area because temperatures below 36°F can damage internal parts. If the heater must be placed where freezing may occur, the water needs to be drained before cold weather arrives.

Installation is a contained process handled by trained professionals. Homeowners mainly need to choose a suitable location inside the conditioned space and confirm that their electrical service is adequate. Once it’s installed, the unit runs without further attention apart from occasional inspections by a service technician.

Pros and Cons

Final Thoughts

The Tempra 29 Plus is a remarkably good tankless water heater with a few clear strengths. Advanced Flow Control helps hold temperature when demand spikes. The unit reaches 99%+ efficiency and runs near silently. A bright LED display, a simple dial, and two memory presets make daily control a doddle.

This is a high-power electric heater, so confirm electrical capacity before buying. The unit draws up to 28.8 kW at full output. It provides reliable flow rates for typical household use and has the solid build quality you expect from Stiebel. For those who want a dependable, easy-to-use on-demand hot water system, it is an excellent choice.

FAQ: Stiebel Eltron Tempra 29 Plus