Guides / Water heaters · Updated
Stiebel Eltron Tempra 36 Plus: breakers, wire and gpm for your water
From Stiebel Eltron's own spec sheets, read November 2026.
Short answer
The Stiebel Eltron Tempra 36 Plus draws 150 A at 240 V and needs three 50 A double-pole breakers. Stiebel Eltron recommends at least 300 A electrical service. With 37°F winter water it makes 3.6 gpm of 105°F water; with 77°F water, 8 gpm.
Flow by incoming water temperature
| Incoming water | 37°F | 42°F | 47°F | 52°F | 57°F | 62°F | 67°F | 72°F | 77°F |
|---|---|---|---|---|---|---|---|---|---|
| gpm at 105°F | 3.6 | 3.9 | 4.2 | 4.6 | 5.1 | 5.7 | 6.5 | 7.5 | 8 |
A shower uses 2.0 gpm with a WaterSense head or 2.5 gpm with a standard one, so divide by that for showers at once. Stiebel Eltron's sizing guide says to step up one model on 208 V.
Specs
| Power | 36 kW at 240 V |
|---|---|
| Current | 150 A |
| Breakers | three 50 A double-pole |
| Wire | three runs of 8/2 AWG copper |
| Recommended service | 300 A |
| Starts at | 0.77 gpm |
| UEF | 0.98 |
Can your panel run it?
150 A is a big share of any house. The electric water heater circuit check adds it to your house's load and tells you whether your main breaker has room. For a gas or heat pump alternative, compare running costs with the water heater cost calculator.