is a self-help website
Figure volts amps watts for water heater Compare 16 ways to control water heater
How to install point of use water heater Point of use water heater
Search waterheatertimer.org / all results
Search using Find button  

 Tweet button  

Basic 240 & 120 volt water heater circuits

Dia 1) Typical residential water heater: 240 Volt 4500 watt:

Black and White wires are hot > bare copper is ground
240 volt water heater circuit
Back to connect wires

When using black-and-white wires for 240Volt, add tape to white wire.
This action will tell next electrician that white wire carries power

Breaker box

Dia 2) Typical residential water heater: 240 Volt 3500 watt

240 volt water heater circuit
30 amp 10 gauge wire supports up to 5500 watt non-simultaneous water heater

20 amp 12 gauge wire supports up to 3800 watt non-simultaneous water heater

Read label on side of water heater.

Using 12 gauge wire on 4500 watt water heater can overheat wire and breaker, causing shortened breaker life and possible damage to breaker panel busbar

Using 12 gauge wire on 5500 watt water heater will blow breaker

Figure volts amps watts for water heater
Choose correct wire and breaker size

Dia 3) 240 Volt circuit with neutral wire: uncommon

Not typically found in residential water heater circuits
Black and Red wires are hot > bare copper is ground > white is neutral
240 volt water heater circuit 
Larger image

How to wire thermostats
How thermostats work

Dia 4) 120 Volt water heater circuit: for under counter water heater 

Typical example of under-counter water heater
Black wire is hot > white wire is neutral > bare copper is ground
120 Volt water heater circuit
Water heater will work on any voltage
Convert 240V water heater to 120V
Connect water heater to generator
color-code household wire
Wire sizes

Wire connectors and how to twist wire
How to install under counter water heater
Convert water heater to 120 volts

Main breaker
Larger image

Ordinary Main panel for home has 120 volt and 240 volt circuits.

This is called single-phase electric power. Phasing is determined by the power company.

- Each 120 volt circuit can include up to 12 outlets, and supply power to lights inside a room.
- Generally each 120 volt circuit sends power to one area of home. This is because the wire leaves breaker box and goes to first junction box inside a room. From the junction box, the wire splits off and goes to each individual box, jumping from box to box until the final box is reached. So each box will have 1 black hot wire, 1 white neutral wire, and 1 ground wire that connect back to main breaker box.
- Some circuit breakers are dedicated to 1 specific appliance. For example the kitchen microwave is usually wired to 1 circuit breaker and no other outlets or lights are connected to that breaker. This is because microwave draws so much amperage. That is called dedicated circuit, and dedicated breaker.

- Each 240 volt circuit is usually dedicated to one appliance. For example electric water heater is connected to 1 240 volt breaker. The electric dryer is connected to another 240 volt breaker. The heat/AC is connected to another 240 volt circuit breaker, and so on.
See inside main breaker box
How to replace circuit breaker
How to install subpanel
Figure volts amps watts for electric water heater

Additional links
Basic household wiring
Basic water heater circuit

Figure volts amps watts for electric water heater
Test elements
Replace elements
How to wire tankless electric
How to change water heater temperature using timer
Change water heater from 240Volt to 120Volt
Replace thermostats
How to wire thermostats
How to wire water heater for off peak operation

How to twist wire
How to wire Cooper 277 pilot light switch
How to wire combo switch-outlet
How to replace 3-speed fan switch

How to wire dimmer
How to wire 3-way dimmer
How to wire occupancy switch
How to wire motion detector
How to wire TM811 and TM8111 switches
How to wire wall timers
How to wire box timers
How to wire off-delay timer
Wire off-delay timer
How to wire pin timers

How to wire and troubleshoot photo eyes
Reverse photoeye so it turns on in day
24 Volt photoeye
24 volt programmable timer

How to wire switches
How to add switch
How to add 3-way switch

Timer for 3-way switch
Timer for 4-way switch

How to add outlet 
How to wire 3-way switches
How to wire 4-way switches

Troubleshoot Malibu outdoor lights
Select and install wire connectors
Select wire size

Electrical formulas
Electricians forum

Electrical pages

How to wire arc fault breaker
How to wire GFCI
How to wire GFCI combo

Basic water heater circuit
How to wire water heater for 120Volt
Install old work box

How to drop wire from attic
Wire connector

How to wire 240volt outlets
How to install 3-phase timer
How to wire 3-phase outlets
How to wire 3-phase surge protector
What is 3-phase

How to wire whole house surge protector
How to wire under-counter water heater

See inside main breaker box
Replace breaker
Install subpanel

How to solder wires
Whole house surge protector
3-phase surge protection
Circuit breakers

Difference between 120 volt and 240 Volt
Difference between 50Hz and 60Hz
How to install electric meter on water heater
How to wire water heater thermostat
How to wire water heater with switches and timers

6x6x4 Enclosures
Intermatic timer enclosures

Convert AC water heater to DC
How to wire DC solar water heater
DC relays for solar water heater
How to add another thermostat to water heater

How many Kwh to heat water
Chart for figuring heating time for electric heater

Gas and electric water heaters Industrial electric at Amazon

Industrial supplies at Amazon

Industrial and scientific Amazon
Shop Amazon - DEWALT
Shop Amazon - Black and Decker
Shop Amazon - Stanley Tools
Shop Amazon - SKIL Tools
Shop Amazon - Porter-Cable Tools
Shop Amazon - Bosch Tools
Shop Amazon saws and saw blades
box timers Compare box timers

Control water heater w/ Z-wave
Intermatic control centers Control centers:
+ manuals and parts

All control centers and parts

Including Z-wave
programmable timer Compare programmable timers

Control water heater with programmable wall timer
Countdown timers Compare countdown timers

Control water heater with countdown timer
Low voltage power packs Low voltage transformers
E-mail: geno03245w@gmail.com
My response might end up in spam folder, check email folders
Site map
Follow newest idea on twitter
Privacy policy