Electric tankless water heaters deliver endless hot water on demand, but they place serious demands on your home's electrical system. A single whole-house tankless unit can draw 100 to 150 amps at peak operation -- requiring two or three dedicated 40-amp circuits with heavy-gauge wiring run directly from your electrical panel. This is not a plug-and-play appliance. It is a major electrical installation that must be done correctly.
Many Aiken homeowners are surprised to learn that their existing electrical panel cannot support a tankless water heater without an upgrade. Older homes with 100-amp or 150-amp panels simply do not have enough capacity. Unity Power & Light handles the complete electrical side of tankless water heater installation -- from panel capacity evaluation to dedicated circuit installation to final connection and testing. We make sure your system is safe, code-compliant, and sized correctly for your household's hot water needs.
What We Do
Tankless water heater electrical work goes far beyond running a single wire. Here is what a proper installation involves.
Panel Capacity Assessment
Before any wiring begins, we evaluate your electrical panel to determine whether it can handle the additional load. Most electric tankless units require 120 to 150 amps of dedicated capacity. If your panel is at or near its limit, we recommend a panel upgrade before proceeding.
Dedicated 40-Amp Circuits
Electric tankless heaters typically require two or three dedicated 40-amp, 240-volt circuits. Each circuit runs directly from the panel to the unit with no other loads sharing the wire. We install double-pole 40-amp breakers for each circuit as required by the manufacturer.
Proper Wire Gauge Selection
Each 40-amp circuit requires 8-AWG copper wire at minimum. For longer runs, we may step up to 6-AWG to prevent voltage drop that can cause the unit to underperform. We calculate the exact wire size based on the distance from your panel to the installation point.
Panel Upgrades
If your current panel lacks the capacity for a tankless water heater, we upgrade it. This often means moving from a 100-amp or 150-amp panel to a 200-amp service. We handle the panel replacement, meter coordination with the utility, and all required inspections.
Breaker Sizing & Protection
Each circuit must be protected by the correct breaker size specified by the heater manufacturer. Oversized breakers create fire hazards. Undersized breakers cause nuisance tripping. We match the breaker to the unit's exact specifications every time.
Final Connection & Testing
After all circuits are run, we make the final electrical connections at the unit, verify proper voltage at each terminal, test the unit under load, and confirm that all breakers hold without tripping during peak demand operation.
Our Installation Process
Evaluate Your Panel and Load
We inspect your existing electrical panel, calculate current demand from all circuits, and determine how much spare capacity is available. If your panel cannot support the additional load, we discuss upgrade options before any work begins. This step prevents costly surprises mid-installation.
Plan the Circuit Routes
We map the most efficient path from your panel to the heater location. Shorter runs mean less voltage drop and lower material costs. We identify any obstacles -- finished walls, crawl spaces, attic access -- and plan the routing to minimize disruption to your home.
Install Circuits and Breakers
We run the dedicated circuits using the correct wire gauge, install double-pole breakers in your panel, and secure all wiring to code. Each circuit is labeled clearly at the panel for future reference. If a panel upgrade is needed, that work is completed first.
Connect, Test, and Verify
We make the final connections at the tankless unit, verify voltage and amperage readings on every circuit, run the unit through a full heating cycle, and confirm reliable operation. We walk you through the system and leave all breakers clearly labeled.
Why Professional Installation Matters
Tankless water heater wiring is high-amperage work that carries serious risks if done incorrectly. Here is why professional installation is essential.
Fire Risk from Undersized Wiring
Drawing 40 amps through wire that is too thin causes the conductor to overheat. Over time, this degrades the insulation and creates a fire hazard inside your walls. A licensed electrician calculates the correct wire gauge for the amperage and the length of the run, eliminating this risk entirely.
Panel Overload Protection
Adding 120 to 150 amps of load to a panel that is already near capacity can cause main breaker trips, voltage sags, and damage to other appliances. We perform a full load calculation before installation to ensure your panel can handle the demand safely and reliably.
Manufacturer Warranty Requirements
Most tankless water heater manufacturers require installation by a licensed electrician to maintain the product warranty. If the electrical work is not done to spec and the unit fails, the manufacturer can deny your warranty claim. Our licensed installation protects your investment.
Code Compliance and Permits
Tankless water heater electrical installations require permits and inspections in Aiken County. Work performed without a permit can create problems when you sell your home. We pull all required permits and schedule inspections as part of every installation.
Tankless Water Heater Wiring Pricing
Unity Power & Light provides flat-rate pricing for tankless water heater electrical work. You will know the exact cost before we begin -- no hourly billing and no surprise charges.
The final price depends on your panel's current capacity, the distance from the panel to the heater location, the number of circuits required by your specific unit, and whether a panel upgrade is necessary. We provide an exact quote after evaluating your electrical system.
For more details on what affects the cost of tankless water heater electrical work, read our blog post: Tankless Water Heater Electrical Requirements in Aiken, SC
Why Choose Unity Power & Light
Need other electrical work done at the same time? We offer a full range of residential electrical services including panel upgrades, outlet installation, and more. Combining projects in a single visit saves you time and money.
Need Tankless Water Heater Wiring?
Serving Aiken, SC and surrounding communities including North Augusta, Graniteville, New Ellenton, Jackson, and Clearwater. Get your flat-rate quote today.