Stiebel Eltron DHC 8-2 Classic Electric Tankless Water Heater User Manual

1. Introduction and Overview

This manual provides essential information for the safe and efficient operation of your Stiebel Eltron DHC 8-2 Classic Electric Tankless Water Heater. The DHC 8-2 is a point-of-use electric tankless water heater designed to provide hot water instantly at a single sink or low-flow application. Its compact design and energy-efficient operation make it suitable for various installations where hot water is needed on demand.

Please read this manual thoroughly before installation and use to ensure proper function and to prevent potential hazards.

2. Safety Information

Important Safety Instructions:

Installation must be performed by a qualified electrician and plumber in accordance with all national, state, and local electrical and plumbing codes.
Disconnect all power to the unit before performing any service or maintenance.
Do not operate the water heater if it is damaged or malfunctioning.
Ensure proper grounding of the unit to prevent electrical shock.
Water temperatures can reach levels that cause scalding. Exercise caution when using hot water.
This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.

3. Product Features

The Stiebel Eltron DHC 8-2 is engineered for efficiency and reliability:

Energy Efficiency: Up to 50% less power consumption compared to traditional storage tank heaters.
Instant Hot Water: Provides hot water on demand, eliminating standby heat loss.
Quiet Operation: Hydraulically controlled system ensures minimal noise during use.
Safety: Equipped with a resettable safety high limit switch for protection against overheating.
Cost-Effective Installation: Generally lower installation costs compared to tank-type units due to compact size and simplified plumbing.
Durable Heating Element: Features an exclusive copper-clad heating element designed for longevity and resistance to dry-firing.
Reliability: Engineered for superior long-term performance.

Stiebel Eltron DHC 8-2 Classic Electric Tankless Water Heater exterior view

Figure 1: Exterior view of the Stiebel Eltron DHC 8-2 Classic Electric Tankless Water Heater. This image shows the compact, white casing with the Stiebel Eltron logo.

4. Technical Specifications

Specification	Value
Model	DHC 8-2
Part Number	202653
Voltage	240V / 208V
Wattage	7.2 kW / 5.4 kW
Amperage	30A / 26A
Min. Recommended Circuit Breaker Size	30A / 30A
Min. Recommended Wire Size	10/2 AWG
Minimum Water Flow to Activate Unit	0.69 gpm (2.6 l/min)
Nominal Water Volume	0.13 gal (0.5 l)
Max. Permissible Inlet Temperature	86 °F (30 °C)
Working Pressure	150 psi (10 bar)
Tested to Pressure	300 psi (20 bar)
Water Connections	3/8" NPT
Dimensions (W x H x D)	7-15/16" (20.2 cm) x 14-3/16" (36.0 cm) x 3-7/8" (9.8 cm)
Weight	5.5 lb (2.5 kg)

Energy Guide label for Stiebel Eltron DHC water heaters

Figure 2: Energy Guide label for Stiebel Eltron DHC series water heaters. This label provides estimated yearly operating cost and energy use information, noting that specific data for tankless electric water heaters may not be available.

5. Installation

The Stiebel Eltron DHC 8-2 water heater must be installed by a licensed professional. Improper installation can lead to property damage, injury, or death, and will void the warranty. Refer to the detailed installation instructions provided with the physical product for specific steps and diagrams.

Key Installation Considerations:

Location: Install the unit as close as possible to the point of use to minimize heat loss and maximize efficiency. Ensure adequate clearance for servicing.
Mounting: Securely mount the unit to a solid surface capable of supporting its weight when full of water.
Plumbing: Connect the cold water inlet and hot water outlet using appropriate fittings. Ensure all connections are watertight. The unit requires a minimum water flow of 0.69 GPM to activate.
Electrical: Connect the unit to a dedicated electrical circuit with the specified voltage (240V/208V) and amperage (30A/26A). Use the recommended wire size (10/2 AWG) and circuit breaker (30A). Ensure proper grounding.

Internal components of Stiebel Eltron DHC 8-2 water heater with labels

Figure 3: Internal view of the Stiebel Eltron DHC 8-2 water heater. Key components are labeled, including the heater, safety thermal cut-out, flow switch, wiring block, hot water connection, and cold water connection. This diagram is for reference during professional installation and servicing.

6. Initial Setup and Operation

After professional installation, follow these steps for initial setup:

Flush the System: Before connecting electrical power, open the hot water faucet at the fixture served by the DHC 8-2. Allow water to flow through the unit for several minutes to purge any air from the system. This prevents damage to the heating element.
Check for Leaks: Inspect all plumbing connections for leaks. Tighten any connections as necessary.
Apply Power: Once the system is fully purged of air and free of leaks, turn on the electrical power to the unit at the circuit breaker.
Operation: The DHC 8-2 is a flow-activated unit. When a hot water faucet is opened and the water flow exceeds the minimum activation rate (0.69 GPM), the unit will automatically energize and begin heating water. The unit will de-energize when the flow drops below the minimum activation rate or the faucet is closed.

The DHC 8-2 does not have external temperature controls. The output temperature is dependent on the incoming water temperature and the flow rate. For optimal performance, ensure the flow rate is consistent with the unit's specifications for your desired temperature rise.

7. Maintenance

The Stiebel Eltron DHC 8-2 is designed for minimal maintenance. However, periodic checks can help ensure long-term performance:

Visual Inspection: Annually inspect the unit for any signs of leaks, corrosion, or damage.
Water Quality: In areas with hard water, mineral deposits (scale) can accumulate over time, potentially affecting performance. If a decrease in hot water flow or temperature is observed, professional descaling may be required. Contact a qualified plumber for this service.
Inlet Screen Filter: Some installations may include an inlet screen filter. Check and clean this filter periodically to ensure unrestricted water flow.

Always disconnect power to the unit before performing any maintenance.

8. Troubleshooting

If you experience issues with your DHC 8-2, consult the following troubleshooting guide. For problems not listed or if solutions do not resolve the issue, contact a qualified professional or Stiebel Eltron customer support.

Problem	Possible Cause	Solution
No hot water or insufficient hot water.	No power to the unit. Water flow below minimum activation rate. Safety high limit switch tripped. Inlet water temperature too low for desired output. Mineral buildup (scale) in the unit.	Check circuit breaker. Increase water flow at the faucet. Disconnect power, wait 10 minutes, then press the resettable safety high limit switch (located inside the unit, requires professional access). Reduce flow rate at the faucet to allow more heating time. Contact a qualified plumber for descaling.
Water is lukewarm.	Flow rate too high. Inlet water temperature too low.	Reduce water flow at the faucet. The unit's heating capacity is fixed; consider if the unit is appropriately sized for your application and inlet water temperature.
Water leaks from the unit.	Loose plumbing connections. Internal component failure.	Immediately turn off water supply and electrical power. Tighten connections. If leak persists, contact a qualified plumber or Stiebel Eltron support.

9. Warranty and Support

Stiebel Eltron products are manufactured to high-quality standards. For specific warranty terms and conditions, please refer to the warranty card included with your product or visit the official Stiebel Eltron website. Keep your proof of purchase for warranty claims.

For technical assistance, parts, or service, please contact Stiebel Eltron customer support. Ensure you have your model number (DHC 8-2) and serial number ready when contacting support.

Stiebel Eltron Contact Information:

Please refer to the official Stiebel Eltron website or product packaging for the most current contact details.