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How to Wire a Replacement Water Heater
How do I wire a new water heater when the wiring is different than the old water heater?
Wiring a Water Heater
Electrical Question: How should a Replacement Water Heater wired when the wiring looks different?
Mark in Idaho asks:
- How do I wire a new water heater when the wiring is differently than the old water heater?
The existing water heater is wired with 4 wires. The one I am replacing it with only has three wires can you still wire it so it works.
Steve in Florida asks:
- I went to rewire a 240v water heater in my old home and was shocked (pun intended) to find a white wire used as a hot and a ground wire of a lesser AWG, used as the neutral. There wasn’t even a neutral wire on the water heater itself.
- The shock continued when I found out the electric range and central air conditioner were wired the same way.Isn’t it considered bad practice to run current on a ground wire as part of normal operation?
- Also, should that ground wire then be at least of an equal AWG to the hot wires as it will be carrying the same amperage?
Thanks for your electrical wiring questions.
Wiring a Replacement Water Heater
Application: How to Wire a Replacement Water Heater.
Skill Level: Intermediate to Advanced – This project is best performed by a Licensed Electrical Contractor, or Licensed Plumbing Contractor.
Electrical Tools Required: Basic Electricians Pouch Hand Tools, Voltage Tester, and appropriate Safety Gear.
Estimated Time: Depends on the personal level experience, ability to work with tools, install electrical circuit wiring, and the available access to the project area.
Electrical Safety: Identify the electrical power source to the Water Heater, turn it OFF and Tag with a Note before working with the electrical wiring.
Electrical Wiring Parts and Materials: Electrical parts and materials for the Water Heater should be approved for the specific project and compliant with local and national electrical codes.
Electrical Codes and Inspections: Installing or changing home electrical wiring should be done according to local and national electrical codes as adopted in your specific area. A permit and inspections may also be required.
Wiring Connections for a Water Heater
This electrical wiring project is about How to Wire a Water Heater in a residential home.
How to Wire a New Replacement Water Heater
- For Mark in Idaho, from the information you have provided, it is important to make sure the voltage and amperage of the existing water heater circuit matches the electrical specifications of the new water heater.
- You may discover that there is an additional white neutral wire that is not required for the new water heater, however this too should be verified.
- When the electrical circuit has been checked and verified to meet the specifications of the new water heater, the wiring connections can be made correctly for the line wire connections and the ground connection.
Water Heater Circuit Wires
- For Steve in Florida, from what you have described, there are several instances in older homes where a white wire is used as a hot wire for a 240volt dedicated circuit, such as you have found for the water heater.
- Typically the original electrician would have colored the white wire of a 240volt circuit with red or black electrical tape or permanent marker, unfortunately this was not done, however now that can be corrected.
- Note: Typically a 240volt conventional water heater does not require a neutral wire, only two hot wires and a ground wire of a dedicated circuit, and yes – some of the older cables had a ground wire that was a smaller gauge size wire.
See More about How to Wire a Water Heater
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