How to Wire a 240 Electric Hot Water Heater

Wiring a 240 Volt Alternating current (VAC) water heater can be accomplished in an afternoon by following a basic process. Understanding the correct wiring to use will create a safe installation. If the water heater is rated for 30 amperes at 240 VAC the proper wire size will be a 10/2 with ground Romex cable assembly. A higher amperage electric water heater that is rated for 40 amperes at 240 VAC will need an 8/2 with ground cable assembly. The circuit breaker must match the rating of the water heater circuit. In other words a 30 ampere circuit requires a 30 amp breaker as does a 40 amp wire need a 40 ampere breaker. By installing the water heater yourself, you can definitely save a few dollars in your pocket and have hot water ready to go.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Screwdriver Philips or slotted Properly sized and type 240VAC, 30 or 40 amp circuit breaker 10/2 or 8/2 with ground cable assembly Cable to box connectors Pocketknife Wire strippers Wire pliers Wire nuts

1. Disconnect the power to the circuit breaker panel box by turning "off" the main power switch.

2. Remove the protective cover of the panel box and set aside the cover screws so you do not loose them.

3. Install the new 240 VAC 30 or 40 amp breaker onto the bus bar of the distribution panel. The breaker will either screw onto the main bus bar or "pop" into place and lock under a set of raised metal bars on the backside panel case. The new breaker should be in the "off" position.

4. Run the cable wire assembly from the main panel box to the hot water heater location. Pay particular attention so as not to nick or break the outer insulation covering.

5. Install the cable connectors into the round opening provided in the panel box and the cable entrance to the water heaters electrical make up box. You may have to break out the metal disc of the properly sized "knock out" hole with the screwdriver and wire pliers.

6. Feed the cable through the connector, leaving enough wire assembly to comfortably terminate the wires. It is always a good idea to have too much wire as not enough.

7. Strip the outer insulation from the cable assembly with the pocketknife and strip away one inch of the wire insulation using the wire strippers. You should have a black wire, white wire and a bare copper wire. There should be one inch of bare copper showing on the black and white wires.

8. Terminate the circuit breaker wires, feed wires, into the two screws on the 240 VAC breaker. The black wire will go to one screw and the white wire to the other. The bare copper wire will be screwed to the silver colored neutral bar mounted on the backside of the panel box.

9. Wire the electric hot water heater. Use the wire pliers and twist one of the hot water heaters wires to the black wire and then the white wire to the other heater wire. Be sure you have a good twist mechanical connection of the two bare copper wire ends.

10. Screw the bare copper wire to the green grounding screw on the hot water heater.

11. Apply a wire nut to each of the two feed wire connections in the water heater make up electrical box.

12. Fold the wires into the makeup box and screw down the cover on the hot water heater.

13. Replace the cover on the panel box and return the main switch to the "on" position.

14. Switch on the new circuit breaker to the water heater and proceed to the location of the new hot water tank. You should be able to hear the electric elements energizing in the cold water. It will have a sound that resembles a coffee percolator.

Tips & Warnings

• Follow all state and local electrical codes whenever installing new electrical devices. Electricity can cause serious injuries, even death. Use caution.