Stiebel Eltron Water Heater Installation Guide

Stiebel Eltron install requirements vary dramatically by product family. Whole-house Tempra Plus is contractor work involving major electrical service. Mini and SHC are homeowner-friendly plug-in installs. Plan carefully — electrical service capacity is often the limiting factor on whole-house electric tankless.

Tempra Plus whole-house tankless — electrical

Tempra Plus draws huge continuous amperage. Verify your service panel before purchasing:

Tempra 36 Plus continuous draw: 150A. Your service panel must have spare capacity above and beyond existing loads. Many 200A services are already at 80-90% capacity; adding a Tempra 36 Plus requires either service upgrade or Stiebel\'s Smart Energy Logic load-shed switch.

Tempra Plus — water connections

• ¾" NPT cold inlet and hot outlet
• Inlet filter (recommended Stiebel filter or equivalent 80-mesh)
• Shutoffs on both inlet and outlet
• Pressure relief valve (combination T&P) — some installs use external T&P
• Tempra Plus is for indoor install only — does not tolerate freezing

Tempra Plus — mounting

• Wall-mount, vertical orientation
• Clearances per manual — typically 1-2" sides, 24" front for service
• Within 100 ft of farthest fixture for reasonable wait time
• NOT in unconditioned space (would freeze)

DHC point-of-use install

• 240V dedicated breaker (20-40A depending on model)
• 10/2 or 8/2 NM cable depending on amperage
• Inlet filter recommended
• Wall-mount under sink or in cabinet
• ¾" or ½" plumbing depending on model
• No flue, no condensate

Mini under-sink install

• Standard 120V outlet — no electrical work needed
• Under-sink or in-cabinet mount
• ½" plumbing connections
• Drip pan recommended (small unit, but small leaks possible)
• Compatible with low-flow aerators — verify 0.3 GPM activation

SHC mini-tank install

• Standard 120V outlet
• Floor-stand under sink OR wall-mount bracket (sold separately)
• ½" plumbing
• T&P discharge tube to safe location
• Drain valve at bottom of tank
• No electrical work — plug-in

Accelera 300 E heat pump install

• 240V 15A dedicated breaker (lowest amperage among the lineup — heat pump compressor only)
• 700+ cubic feet unconditioned air space around the unit. Closet install requires louvered doors with 240 sq in ventilation
• Condensate drain — gravity to floor drain OR condensate pump ($120 add-on)
• Ambient temperature 45-95°F for full heat pump operation
• Drain pan required indoor or above living space
• Floor-stand; verify floor can support 245 lb dry, 920 lb full
• Service clearance: 12" sides, 24" front, 24" top

Service panel evaluation for Tempra Plus

Before ordering a Tempra Plus, evaluate:

1. Service size — 200A is typical residential; 100A or 125A panels rarely accommodate whole-house electric tankless
2. Current load — sum existing breakers including AC, electric range, electric dryer, EV charger
3. Spare capacity — NEC 220 calculation; consult an electrician
4. Service upgrade cost — $2,500-5,000 if needed; factor into project cost
5. Smart Energy Logic alternative — Stiebel\'s load-shed switch can let Tempra share circuit capacity with another large load (range, EV charger). Limited applications but can avoid service upgrade

DIY vs contractor

• Tempra Plus: contractor work — licensed electrician for service-panel changes, licensed plumber for water connections
• DHC point-of-use: licensed electrician for 240V circuit; plumbing DIY-able
• Mini under-sink: homeowner DIY (plug-in 120V, plumbing skills required)
• SHC mini-tank: homeowner DIY (plug-in 120V)
• Accelera: contractor work — 240V circuit, condensate drain, possibly drain pan add

Bottom line

Tempra Plus is electric service-intensive. Verify panel capacity BEFORE buying. Mini and SHC are homeowner-friendly. Accelera is contractor work but lower-amperage than expected (15A!). Always use the manufacturer\'s spec sheet for breaker and wire sizing — Stiebel\'s requirements are absolute, not suggestions.