Section 6
Point-of-use electric tankless water heaters: rise, amps and flow
This page lists temperature rise, amp draw, breaker size and activation flow for Stiebel Eltron DHC-E Classic and Mini point-of-use heaters. A point-of-use heater sits at one sink or one shower and needs no long hot water pipe run. It can serve a garden office, a cabin washroom or an ADU kitchen far from the main heater.
| Model | Power | Amp draw | Breaker | Activation flow | Rated points |
|---|---|---|---|---|---|
| DHC-E 8/10 Classic (set to 9.6 kW) | 9.6 kW | 40 A | 1 x 40 A DP | 0.264 GPM | 0.75 GPM at 87 F, 1 GPM at 66 F, 1.5 GPM at 44 F |
| DHC-E 8/10 Classic (set to 7.2 kW) | 7.2 kW | 30 A | 1 x 30 A DP | 0.264 GPM | 0.75 GPM at 66 F, 1 GPM at 49 F, 1.5 GPM at 33 F |
| DHC-E 12 Classic | 12 kW | 50 A | 1 x 50 A DP | 0.264 GPM | 1 GPM at 82 F, 1.5 GPM at 54 F, 2.25 GPM at 36 F, 3 GPM at 27 F |
Source: DHC-E Classic technical specifications[1]. The 8/10 is one unit set by a jumper at installation to 7.2 kW or 9.6 kW.
| Model | Power and draw | 42 F | 52 F | 62 F | 72 F |
|---|---|---|---|---|---|
| Mini 2-1 / Mini-E 2-1 | 1.8 kW, 120 V, 15 A | 0.3 | 0.3 | 0.3 / 0.4 | 0.3 / 0.4 |
| Mini 2.5-1 / Mini-E 2.5-1 | 2.4 kW, 120 V, 20 A | 0.3 | 0.4 | 0.6 | 0.9 |
| Mini 3-1 / Mini-E 3-1 | 3.0 kW, 120 V, 25 A | 0.4 | 0.5 | 0.7 | 1.1 |
| Mini 3.5-1 / Mini 4-2 | 3.5 kW (120 V, 29 A) / 3.5 kW (240 V, 15 A) | 0.5 | 0.6 | 0.85 | 1.3 |
| Mini 6-2 | 5.7 kW, 240 V, 24 A | 0.8 | 1 | 1.4 | 2.2 |
Sources: Mini and Mini-E sizing guide[2] and technical specifications[3]. Stiebel Eltron says these units are designed for handwashing sinks only. Two numbers in a cell are the mechanical and thermostatic versions. The guide does not give the outlet temperature for this table, so these rows are not used in the sizer.
6.3 Limits of 120 V units
The 120 V Mini models go up to 3.5 kW. At 42 F water Stiebel Eltron lists 0.3 to 0.5 GPM for them, which is the flow of a hand sink with a restrictor aerator. A shower needs a 240 V unit such as the DHC-E 12. Its sheet lists a 54 F rise at 1.5 GPM[1], which takes 52 F water to about 106 F.
Each Mini ships with a pressure-compensating aerator that must be installed. The aerator is 0.35 to 1.0 GPM, by model[3]. A faucet without that aerator runs faster than the heater can heat the water.
The amp draw and breaker sizes are Stiebel Eltron's numbers. The circuit for a point-of-use heater is work for a licensed electrician, and the manufacturer's manual governs the installation.