Best Stiebel Eltron Tankless Water Heaters 2026: Tempra 24 vs 36 Plus, Every Model Sized

Quick Answer: The best Stiebel Eltron tankless water heater for most homes is the Tempra 24 Plus (24 kW) — a German-built whole-home electric unit rated up to 4.68 GPM with Advanced Flow Control, usually around $650, and Stiebel’s own recommendation for Northern-U.S. and Canadian homes where inlet water drops below 45°F. Cold-climate or high-demand homes should step up to the 36 kW Tempra 36 Plus (up to 7.03 GPM, ~150A service); warm-climate and smaller homes save money and wiring with the Tempra 20 Plus or 15 Plus; and a single remote sink is covered by the tiny Mini 3-1. Every GPM figure is a warm-inlet maximum — your cold-winter reality is lower, so size to your coldest month.

Stiebel Eltron is the premium name in electric tankless: German-engineered, 99% efficient at the unit, and the only major brand whose whole-home heaters use Advanced Flow Control — a patented feature that slightly throttles flow to hold your set temperature instead of letting the water go lukewarm when demand spikes. You pay more per kilowatt than an EcoSmart or a Rheem RTEX, but you get the steadiest shower in the category. This guide ranks every current Stiebel Eltron line for 2026 and shows you how to pick one by climate, electrical service, and the one decision that trips up most buyers: Plus versus Trend.

Tempra Plus vs Tempra Trend, decoded

Stiebel Eltron sells the same Tempra hardware in two trims, and choosing the wrong one is the most common Stiebel buying mistake:

• Tempra Plus — the full-feature line. Adds Advanced Flow Control, a digital display, two temperature presets, and a flow/energy monitor. When you overtax it, it reduces flow a little to keep the temperature you set — you never get a cold surprise mid-shower.
• Tempra Trend — the value trim. Same self-modulating heating and same kW classes, but no Advanced Flow Control. Overtax a Trend and the outlet temperature drops instead. It’s cheaper and fine for warm climates with predictable demand.
• The number is the kilowatts, not the GPM. Tempra 24 = 24 kW. Watts heat water; gallons-per-minute depend on how cold your incoming water is, which is why Stiebel publishes temperature-rise charts rather than one flow number.

If your household runs two fixtures at once or lives where winter water is genuinely cold, buy the Plus — the flow-throttling is exactly what keeps the shower warm. This guide ranks the Plus line; each pick has a matching Trend model if you want to trade the display and flow control for a lower price.

Our top picks at a glance

By the numbers

• Up to 7.03 GPM on the 36 kW Tempra 36 Plus — the top of Stiebel’s residential range, but a warm-inlet maximum; at a 3.0 GPM draw the 36 Plus delivers an 82°F temperature rise, which is why the same unit is a two-fixture heater in a Minnesota winter and a whole-house machine in Florida. — Stiebel Eltron / Home Depot listing
• 4.68 GPM and ~100A (two 50A double-pole breakers) for the 24 kW Tempra 24 Plus — Stiebel’s recommended whole-home unit for the Northern U.S. and Canada where inlet water drops below 45°F. — Home Depot / Stiebel Eltron
• Advanced Flow Control is patented in Germany and exclusive to Stiebel Eltron — when demand exceeds capacity it automatically reduces flow slightly to maintain a constant temperature, the feature that separates a Plus from every value-brand competitor. — Stiebel Eltron
• ~99% efficient at the unit with no standby tank loss and no venting — the efficiency ceiling for electric resistance heating. — Stiebel Eltron
• Electric tankless is about 24–34% more efficient than a standard storage tank for homes using up to ~41 gallons of hot water a day, per the U.S. Department of Energy — the running-cost case that makes a self-modulating Tempra pay back over time. — U.S. Department of Energy

1. Tempra 24 Plus — Best Overall

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The Tempra 24 Plus is the Stiebel Eltron we’d buy for most homes. Its 24 kW is the class Stiebel points cold-climate buyers toward, and at ~100A (two 50A double-pole breakers) it fits many 200A panels without a service upgrade — unlike the 36 Plus. The up-to-4.68 GPM rating is a warm-inlet figure: in a Northern winter with 40°F supply, plan on two-and-a-half to three fixtures’ worth, which is plenty for a 1–2 bath home. Its natural rivals are the Rheem RTEX-24 and EcoSmart ECO 27, both cheaper — but neither has Advanced Flow Control, so the Tempra is the one that never drops to lukewarm when someone starts the dishwasher. Our best electric tankless roundup walks the full sizing ladder if you’re cross-shopping brands.

2. Tempra 36 Plus — Best for High Demand

If you live where winter inlet water is genuinely cold and you want two showers at once — or you run a big warm-climate home — the Tempra 36 Plus is the Stiebel to buy. Nothing smaller has the kilowatts to hold temperature at a 60–80°F rise. Be honest about the electrical reality, though: 36 kW is roughly 150A of dedicated load, which frequently means a service upgrade on top of the heater. That’s the same math our electric vs gas comparison uses to steer large cold-climate homes toward gas, where a single gas condensing unit can push 9–11 GPM without touching your panel. For a two-bath home in a moderate climate, the 36 Plus is endless, rock-steady hot water with no venting and no gas line.

3. Tempra 29 Plus — Best Large Warm-Climate Home

The Tempra 29 Plus is the pick for a bigger warm-climate house that wants more than two fixtures of headroom but can’t spare 150A for the 36. In Florida, Texas, or Southern California — where winter inlet water stays near 60°F — 29 kW comfortably runs two showers plus a sink. Move north and its real-world flow narrows, at which point the 36 Plus (or a gas unit) is the sounder buy. Size by your coldest-month inlet, not the summer number, and confirm your panel can carry three 40A double-pole breakers before you commit.

4. Tempra 20 Plus — Best Warm-Climate Whole-Home

For a one- or two-bathroom home in a warm climate, the Tempra 20 Plus is the smart-money Stiebel — two 40A breakers, a lower price, and Advanced Flow Control that keeps the shower steady when the kitchen tap opens. Its warm-inlet ceiling is around 4 GPM; expect the top of that in the Sun Belt and less in a cold snap. Where the inlet runs cold or two showers must run together, step up to the 24 Plus rather than fight the ceiling — undersizing is the number-one cause of “lukewarm tankless” complaints.

5. Tempra 15 Plus — Best Small Home / Apartment

For a warm-climate apartment, condo, ADU, or one-bath home, the Tempra 15 Plus delivers Stiebel’s build quality and flow control in the smallest, cheapest whole-home package. Its ~3 GPM warm-inlet ceiling is the same climate lesson at a smaller scale: fine for a single shower plus a sink in the Sun Belt, not enough for a cold-inlet Northern home. If your incoming water runs cold or you need two fixtures at once, jump to the 20 or 24 Plus — the small unit can’t create kilowatts it doesn’t have.

6. Stiebel Eltron Mini 3-1 — Best Point-of-Use / Under-Sink

When the problem is one remote sink that takes forever to run warm, you don’t need a whole-home Tempra — you need a Mini under the cabinet. At ~$220 on a standard 120V circuit, the Mini 3-1 delivers warm water instantly to a single low-flow fixture. It won’t run a shower; it’s the surgical fix for a hand-wash sink, and it pairs neatly with a larger Tempra handling the rest of the house. Need a bit more, or a 240V point-of-use unit for a small shower? Stiebel’s DHC-E line (around $260–290) steps up from here.

How to choose a Stiebel Eltron tankless water heater

• Pick Plus over Trend if temperature stability matters. Advanced Flow Control (Plus only) throttles flow to hold your set temperature; a Trend lets the temperature drop instead. For two-fixture homes and cold climates, the Plus is worth the premium.
• Check your panel before your bathroom count. Tempra 20 = ~80A (2× 40A); Tempra 24 = ~100A (2× 50A); Tempra 36 = ~150A (3× 50A). A panel upgrade often costs more than the heater — get an electrician’s load calc first.
• Size by your coldest-month inlet, not the headline GPM. Every Tempra’s flow rating is a warm-inlet maximum; the winter number is lower. Look up your regional inlet temperature and size to the rise you actually need — the 24 Plus for most Northern homes, 20/15 Plus for the Sun Belt.
• Match the model family to the job. Tempra Plus/Trend = whole-home; Mini and DHC/DHC-E = single-fixture point-of-use. Don’t compare them on kW alone.
• Descale annually in hard water. Even a stainless German heat exchanger scales in hard water; add a scale filter and flush yearly to protect the flow rate.

The bottom line

For most homes, the Stiebel Eltron Tempra 24 Plus is the best Stiebel Eltron tankless water heater — a 24 kW whole-home unit at ~$650 with Advanced Flow Control, a 4.68 GPM warm-inlet ceiling, and Stiebel’s own blessing for cold Northern climates. High-demand and cold-climate homes should move up to the Tempra 36 Plus, larger warm-climate homes to the Tempra 29 Plus, and warm-climate or small homes save real money with the Tempra 20 or 15 Plus; a single remote sink is covered by the Mini 3-1. Stiebel’s whole case is Advanced Flow Control and German durability at a premium price — if a rock-steady shower temperature matters more than the lowest price per kilowatt, it’s the best-engineered electric tankless you can buy. Comparing across brands? Start with our best electric tankless roundup, weigh it against the EcoSmart lineup and the Rheem RTEX line, or read electric vs gas and tankless vs tank if you’re still choosing a fuel.

Check the Tempra 24 Plus price on Amazon →