Tempra 12 Trend: where it fits
The Tempra 12 Trend is the lowest-output model in this six-model family. Its single-circuit arrangement can make it worth comparing when hot-water demand is modest, but the smaller electrical requirement comes with less heating capacity. A project serving one concentrated use pattern needs a different assessment from a home where showers and appliances overlap.
This guide covers Stiebel Eltron Tempra 12 Trend, item 239213. It is an electric tankless heater, with no storage-gallon rating. WHE can help homeowners in Palm Beach Gardens, Jupiter and nearby communities compare it with their existing system. Start with the Stiebel Eltron installation overview if you are still choosing a family.
Electrical ratings at 240 V and 208 V
| Specification | 240 V | 208 V |
|---|---|---|
| Rated input | 12 kW | 9 kW |
| Maximum current draw | 1 × 50 A | 1 × 44 A |
| Manufacturer minimum recommended double-pole breakers | 1 × 50 A | 1 × 50 A |
| Copper wire runs: manufacturer minimum | 1 × 8/2 AWG | 1 × 8/2 AWG |
Stiebel Eltron recommends a 100 A minimum main service for this model, depending on the total electrical load at the property. That is different from the individual branch-circuit ratings above. An electrician must assess the complete installation, including other loads, conductor sizing and applicable requirements. The manufacturer specifies copper conductors rated at least 75°C and sizing to keep voltage drop below 3% under load.
The ratings above describe the manufacturer’s 240 V and 208 V configurations. The lower-voltage input is 9 kW, so a 208 V installation cannot be sized using the higher-output figures. Confirm the actual supply before ordering. These figures are for comparing models, not instructions for changing breakers or wiring.
Hot-water flow depends on temperature rise
At a 77°F inlet and a 113°F outlet, the manufacturer lists 2.27 GPM on its higher-voltage row. That leaves little room for overlapping demand if one fixture already needs most of that flow. At a 59°F inlet the listed output falls to 1.51 GPM. These examples make the 12 Trend a model to size carefully, even in a warm-climate location. We would first ask which fixtures must operate together and what flow they actually use.
| Water temperatures | Higher-voltage row: 220–240 V | 208 V |
|---|---|---|
| 77°F inlet → 113°F outlet (36°F rise) | 2.27 GPM | 1.70 GPM |
| 59°F inlet → 113°F outlet (54°F rise) | 1.51 GPM | 1.14 GPM |
These examples come from the manufacturer’s flow-rate table; its higher-output rows are labeled 220–240 V. Electrical nameplate ratings in this guide are specifically stated at 240 V. The temperatures are comparison conditions, not a prediction of your home’s inlet water. A higher requested outlet temperature leaves less available flow for the same incoming water.
We look at the fixtures you actually want to run together. Shower flow, tub filling and appliance use matter more than a simple bathroom count. Also distinguish water flowing through the heater from mixed water at a faucet. If you want better performance than your current system, describe when it falls short so the proposed replacement addresses that specific problem.
Trend controls and model specifications
The Tempra 12 Trend has electronic temperature control and self-modulating heating power. Trend does not include the Tempra 12 Plus model’s Advanced Flow Control. If demand exceeds the heating capacity, the desired temperature may not be maintained. The capacity display helps show how hard the unit is working; it does not add heating output.
The published UEF is 0.94, and minimum activation flow is 0.37 GPM. The cabinet measures 16⅝ inches wide × 14½ inches high × 4⅝ inches deep in the current technical data table; listed weight is 13.5 lb. Water connections are ¾-inch NPT. These cabinet measurements are separate from the space needed for piping and service.
Plan the location and future service
The installation manual calls for 5 inches of clearance on all sides and a protected location that avoids freezing and routine water splashing. A small wall-mounted cabinet can free floor space, but it still needs accessible connections and a suitable mounting area. Include a wide photo of the proposed location so access and plumbing can be discussed before the estimate is finalized.
Ask about water quality and maintenance access when planning the work. Scale or debris can affect flow, and a tankless unit still needs maintenance. Keep the purchase record, model information and installation documents together for future service. The limited manufacturer warranty lists seven years for qualifying leakage and three years for qualifying defects, subject to its terms; field labor is not included. Follow the product-registration directions supplied with the heater.
Compare the neighboring Tempra sizes
The Tempra 15 Trend raises the 240 V input to 14.4 kW and changes the electrical arrangement to two circuits. The Tempra 20 Trend provides 19.2 kW at 240 V and has a higher main-service recommendation. If the 12 Trend falls short of your demand, moving up involves both plumbing planning and an electrical review; it is not just a different number on the cover.
Read the Tempra 15 Trend and Tempra 20 Trend guides alongside this one, or browse the water-heater model catalog. If electrical work changes the project significantly, our electric water-heater information can help frame a comparison with storage equipment. Compare complete installation scopes, expected use and service access before choosing.
Tempra 12 Trend questions
Is the Tempra 12 Trend enough for a whole house?
Only if the measured demand fits its output. The family’s whole-house description does not guarantee this smallest model will support several fixtures together. Compare the table above with your simultaneous hot-water use and the coldest expected inlet water.
Does the Tempra 12 Trend include Advanced Flow Control?
No. Advanced Flow Control belongs to Tempra Plus. Trend adjusts heating power, but it does not automatically reduce water flow to preserve the selected temperature when demand exceeds capacity. Sizing for the fixtures you intend to use together remains essential.
Can I reuse my electric tank’s circuit?
Compatibility must be checked. At 240 V, the manufacturer recommends one 50 A double-pole breaker. Existing wiring, panel space and service capacity need a qualified electrician’s assessment. A previous electric tank installation does not establish that these requirements are met.
Will this make hot water arrive instantly?
The heater warms flowing water, but water already in the pipe still has to reach the fixture. Tell WHE which taps have a long wait. Heater capacity, pipe length and any recirculation arrangement are separate parts of the assessment.
What should I send for a Tempra 12 Trend estimate?
Send a clear model-label photo, a wide photo of the current heater and connections, your location, and the fixtures you use together. Mention this exact model. An installation estimate starts with a review of those details and the electrical requirements; it does not reserve equipment or an installation date.
Discuss your Tempra 12 Trend installation
For an installation or replacement estimate, call 561-602-9062, text WHE or request a free installation estimate. We review the project before confirming equipment availability, the proposed work and scheduling.
Sources checked October 17, 2026: Tempra Trend family information, technical specifications (revision 6.2025) and operation and installation manual. Confirm current documentation and the exact unit label before installation.