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How to install water heater timer

 Page 1 of 3: Overview /and Gather materials
Skip to Page 2: Connect the wires
Skip to Page 3: Wiring details
install water heater timer Project overview: NO Neutral
Use for timers and switches that do not require Neutral
All zwave and wifi devices require Neutral
Attic installation shown. Applies to any location, and any electric water heater.

Intermatic ST01c timer/ 1 year warranty
ST01a almond
Intermatic ST01K combination timer

Spring wound timers
Leviton LTT countdown

Resources for switches:
Wiring for all switches and timers
Control 2 water heaters with 1 switch
Control water heater with 2 switches
Control 1 water heater with 30Amp switch
install water heater timer Project overview: Requires Neutral
Use any programmable timer, zwave or wifi device that is rated for resistive load.
Use Hot and Neutral from nearby 120 volt outlet to power device.
Rule of thumb: Outlet box will always have Hot and Neutral, Switch box will always have Hot but not always Neutral, Ceiling box with light will always have Neutral but only has Hot when light is on.

Programmable timer
Countdown timer
Zwave switch
Wifi switch

Compare programmable timers
Compare countdown timers
                    Project materials
Intermatic EI500  Grasslin ET616    Choose timer or switch
Intermatic ST01 timer
Spring wound timers

Buy: requires neutral
Programmable timer
Countdown timer
Zwave switch
Wifi switch

Compare programmable timers
Compare countdown timers
Old work boxe Old work box
Use for new switch, timer etc.
Drop wire into wall, Cut hole to fit box, reach in and pull wire through hole, put wire inside box, push wire back into hole as you insert box into hole
Thomas and Betts old work box at Amazon
Old work boxes at Amazon

See How to install old-work box
Contactor Contactor with 240V coil for no Neutral
Contactor with 120V coil for requires Neutral
Contactor controls 30 amp water heater load, rated 1 million operations
240Volt coil 2-pole contactor
120Volt coil 2-pole contactor

Read more about contactors and relays
carlton 6x6x4 junction box
Plastic 6x6x4

6X6X4 Metal box w/ Contactor

Choose metal or plastic 6x6x4 junction box

Plastic box: no pre-drilled holes, but easy to drill... must drill size 3/4" holes for Wire connections, size 1/2" hole for fuseholder, and 3/16" holes for bolts. Plastic box does not need ground screw connected to box.
Buy Plastic
Cantex 6x6x4 PVC plastic enclosure with cover at Amazon
Bud industries 11x7x5 box without knockouts
Metal box has knock-outs for 1/2" and 3/4" connector ... must drill 1/2" hole for fuseholder, drill 3/16"  holes for bolts, and drill and thread hole for 10-32 ground screw. Metal box must be grounded.
Suggest pre-painted steel box for appearance.

Buy Metal
Bud industries 6x6x4
All 6x6x4 metal boxes
Outdoor 6x6x4 box
Hinged door/ 6x8x4

Bud industries boxes at Amazon
Arlington boxes at Amazon

See more about boxes
2T511GA enclosure Choose metal junction box
Fits multiple contactors and relays
see image
Outside dimensions: 9-3/8x 5-1/2 x 3-5/8

Nema 3R indoor/outdoor enclosure with pre-installed ground screw
1/2 and 3/4 knockouts located sides and bottom
Painted metal, weathertight hinged door, locking hasp

2T511GA gray painted
2T2485GA beige painted
tapered drill bit Tapered drill bit for plastic or metal box
Step drill bit for any size hole
Step drill bits at Amazon
Neiko tapered drill bit 1/4"-1-3/8 holes
Black and Decker Complete guide to wiring

See inside main breaker box
household wire
120Volt 14-2 wire will have Black-white wires
240Volt, 10-2 wire can have red-black or white-black wires... always add piece of black tape to white wire when used for 240Volt power. Adding black tape will signal that wire carries power

See wire color code and amp ratings
Lengths of wire

White/ #14 gauge wire for 15 amp
25 foot 14-2 NMB indoor wire with ground
50 foot 14-2 indoor wire with ground
100 foot 14-2 indoor wire with ground
100 foot 14-2 UF outdoor burial with ground
Yellow/ #12 gauge wire for 20 amp
25 foot 12-2 NMB indoor with ground
50 foot 12-2 indoor with ground
100 foot 12-2 UF outdoor burial with ground
#10 wire required for water heater
Orange/ #10 gauge for for 30 amp circuits including water heater
25 foot 10-2 NMB indoor with ground
100 foot 10-2 NMB indoor with ground
50 foot 10-3 indoor with ground
See wire color code and amp ratings
fuseholderBusman fuse holder Buy fuseholder and 15 amp fuse
Used for No Neutral installation
Or when nearby hot wire is not available

Panel mount fuse holders at Amazon
Buy fuseholder at Amazon
Buy fuseholders at Amazon
30 amp fuseholder at Amazon
Ceramic fuses at Amazon

Read about fuseholders
wire nuts      Wire connectors

Wire connectors at Amazon
Push-in wire connector up to 14-12 gauge

How to install wire connector
Optional Indicator light
240Volt Pilot light at Amazon
120Volt pilot light at Amazon
Indicator lights at Amazon
See illustration of 120Volt & 240v pilot light
cable staples Staples and clamps
All wires, conduit and boxes must be firmly attached to structure (2x4, siding etc)

Cable staples plastic
Cable staples metal
1/2" conduit clamp
romex connector Wire connectors
All wires and conduit going into metal or plastic box must be firmly attached to the box

1/2" squeeze connector
1/2" conduit connector

Blue 14-16 gauge wire
Yellow 12-10
Use to connect 120 volt wires to contactor see image
Add solder when crimping to solid wire
Terminal kit with crimp tool
Blue 14 gauge
Yellow 10 gauge
More about terminals
8-32 bolts 8-32 x 3/4" bolt w lock nut
ground screws Ground screws
Needed to connect ground wire to metal box
Not needed with plastic box
Use 10-32 tap to thread hole

100 pack ground screws
You have the materials.
hand Go to Page 2: connect the wires.
Insteon 30 amp z-wave load controller
Insteon load controller manual
Gas and electric water heaters Industrial electric at Amazon

Industrial supplies at Amazon

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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
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