Stiebel Eltron Tempra Plus uses solid-copper heating elements — premium element design compared to the stainless-steel elements common in US-market electric tankless. Solid copper has better thermal conductivity, longer life, and tolerates hard-water scaling better.
Element specs by Tempra Plus model
| Model | Element count | Wattage each | Healthy resistance |
|---|---|---|---|
| Tempra 12 Plus | 2 | 7.2 kW | ~8 Ω |
| Tempra 15 Plus | 2 | 7.2 kW | ~8 Ω |
| Tempra 20 Plus | 2 | 9.6 kW | ~6 Ω |
| Tempra 24 Plus | 3 | 8 kW | ~7.2 Ω |
| Tempra 29 Plus | 3 | 9.6 kW | ~6 Ω |
| Tempra 36 Plus | 3 | 12 kW | ~4.8 Ω |
DHC element specs
| Model | Wattage | Healthy resistance |
|---|---|---|
| DHC 4-2 | 3.8 kW | ~15 Ω |
| DHC 6-2 | 5.4 kW | ~11 Ω |
| DHC 8-2 | 7.2 kW | ~8 Ω |
| DHC 10-2 | 9.6 kW | ~6 Ω |
Symptoms of element failure
- E2 error on Tempra Plus display
- Lukewarm output despite adequate flow and good incoming temp
- Half-power output (one of two/three elements failed in larger Tempras)
- Breaker trips immediately on call for hot water (element shorted)
- Zero output even with adequate flow (all elements failed — rare)
Replacement procedure
- Power OFF at all breakers. Tempra Plus has 2-3 breakers; ALL must be off. Verify with voltage tester
- Close inlet shutoff; open hot tap downstream to relieve pressure
- Open the Tempra cabinet per service manual
- Identify the failed element from ohm test (see element test guide)
- Photograph wiring for reassembly reference
- Disconnect element leads at the contactor
- Unscrew element from chamber (typically threaded with gasket seal)
- Install new element with new gasket
- Reconnect leads per photo
- Restore water first — verify no leaks before powering up
- Restore power at all breakers
- Test operation at a hot tap; verify setpoint maintenance
Critical: never power up dry
Tempra Plus elements are exposed to water in normal operation; powering them up dry destroys them in seconds. Always restore water and verify presence at the unit before flipping breakers.
Cost
- Tempra Plus element (OEM): $75-150 depending on model
- DHC element: $50-100
- Contractor labor: $200-400 for whole-house Tempra; $100-200 for DHC
- Warranty replacement under 3 years parts — Stiebel covers part, homeowner labor
Element lifespan
- Soft water with descaling: 12-18 years typical
- Hard water without softener or descaling: 4-7 years
- Very hard water without softener: 2-4 years (replace with water softener install)
Bottom line
Solid-copper Tempra elements are durable in soft water and serviceable. Hard water dramatically shortens life — install a softener or commit to annual descaling. Always power off ALL breakers and verify water before powering up after replacement.