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How to wire under counter water heater
Strategy for supplying instant Hot water Read more
Under counter water heater

120V hardwire / 3/4" connections/ Fully repairable by homeowner
Reliance water heater
Reliance
Buy:
Reliance hardwire
Reliance plug in
STieBLE
12 ga extension cords
12-2 Southwire cable
Resources
Reliance manual
State manual
American manual

State point of use water heater
Rheem
2-6-10-20 gallon
Side connections/
6 year warranty
Buy:
Rheem point of use
Ariston
RHEEM 28 GAL
12-2 Southwire cable
Resource:
Rheem manual
water heater stand
Buy:
Holdrite
Steel pegboard
Hyloft storage hardware
Garage storage

Plug into 120V 3-prong outlet/ Temperature control on front/ 2.5 - 6 gallon/ Non-generic parts/ Repairable
Ariston water heater
Ariston / Bosch
2.5 - 4 gallon  - 7 gallon
Top connections/
2 year warranty
Buy:
Ariston
Bosch
Resources:
Ariston resources
Bosch P10 P5
State point of use water heater
State / Reliance
American/ are all AO Smith
2.5 - 6 gallon
Top connections/
6 year warranty
Buy:
Reliance 2.5 gal
Resource:
Reliance manual
Emax point of use water heater
Waiwela
2.5 - 4 gallon
Top connections
6 year tank warranty
Buy:
Waiwela
Eemax water heaters
Stiebel Eltron water heater
Resource:
Waiwela mini tank
Eemax manual/ parts
Steible 2.5 manual
 Resource How to wire tankless electric

Tankless/ 120-240V hardwire/ 30 amp 10 gauge wire/ Tankless units are connected to incoming cold water line. Not DIY repair/ cannot be exposed to hard water.
Requires dedicated circuit with no other load on breaker
Resources
 How to wire tankless electric
Match breaker size and wire
tankless under counter
Atmor tankless
2 year parts-7 year leak warranty
120-240 volt models
Buy:
Atmor 240 Volt
EcoSmart water heater
Chronomite water heater
Resources:
Atmor Installation manual
EcoSmart manual
EcoSmart troubleshoot
Chronomite manual
How to wire tankless electric
Bosch powerstar manual



Eemax point of use water heater
Eemax tankless
Hardwire 120 Volt
7" x 11" x 3"
Buy:
Eemax SP3512 120V
Eemax SP35 240Volt

Resources:
Eemax tankless manual
Sell sheet with wire size chart
Troubleshoot
Stieble Etron point of use
Stieble Eltron Mini/ tankless
Tankless
Hardwire 120 Volt
Buy:
Stieble mini 120V
3000 watt 30 amp
Stieble mini 6 240 Volt
5700 watt 30 amp

Resources:
Steible Eltron mini manual
Stieble DCH manual



1) What size tank water heater?
1:3 rule of thumb:
If 1 gallon runs out before hot water arrives, then 3 gallon water heater is correct size.
Before choosing: Look at Hot-cold Options below.

Buy:
Under counter water heaters 
Point of use water heaters 
2) Pay attention to Hot and Cold inlets
If hot-cold inlets are reversed, tank will not perform as expected.
Incoming cold water must connect to Cold inlet at bottom of water heater
under counter water heater
a) Spend more for more hot water.
b) Spend less for less hot water

Buy:
Chrome shut off valves 
3) Connect water heater to hot or cold?
Do you connect the inlet to Cold water source, or connect to hot source (that comes from main water heater)?

Option A: Connect to Hot source
. See image
This option draws hot water from main water heater ... so when the under counter tank runs out of hot water, more hot water arrives from main tank and temperature stays hot.
Advantage: Quick delivery of Hot, with plenty more hot on the way.
Disadvantage: If you are just washing hands or don't use much hot at that tap, then Option A costs more because cold water enters the main water heater each time hot is turned on.

Option B: Connect to Cold source. See image
When using under-counter water heater for hand-washing, this is best option
Advantage: Quick delivery of Hot, without drawing cold water into main water heater.
Disadvantage: The supply of hot at the tap is limited to what the small tank can supply.

Larger image
Option A/ Connect to Hot source:
hot water arrives from main tank as under-counter tank runs out of hot.
Connect hot water source to the cold water inlet on tank
Use teflon tape on threads

Advantage option a: Plenty of Hot water.
Problem with option a: Costs more. Each time small amount of hot is drawn from faucet, equal amount of cold water immediately enters main water heater. This causes the main water heater to operate more.
How to solder pipe
Install under counter water heaterLarger image
Option B/ Connect to Cold source:

spend less/ hot water limited to amount inside under-counter tank.
When using under-counter water heater for hand-washing, this is best option.
When installing tankless, use this option.

Problem with option b: Hot water supply is limited to amount of hot water in under counter tank. Under counter water heater supplies all hot water at faucet.
Advantage option b: Costs less. Each time hot is drawn from faucet, cold water does not enter main water heater.

Connect cold water source to the cold water inlet on tank. Hot source pipe is capped.
Use teflon tape on threads
How to solder pipe

GE20P06SAG
Larger image
shut off valveWhat if... no drain valve on tank?
Some small tank type heater do not come with drain valve.
Install drain valve on cold water inlet
Install shut-off on cold water line

Drain the water heater?
Remove TP valve and siphon water from tank

Buy:
Lead-free ball valve 
Chrome shut off valves 
4) Do not drop water heater
Can break element, or damage outer shell. Interior steel tank would be hard to damage.
Check elements ... if OK, then water heater should work
Do not call the manufacturer and report problem, or warranty will be compromised.
Resource
How to troubleshoot electric water heater
5) Earthquake straps / safety
Earthquake areas ... Secure water heater to structure to avoid pipes and electrical coming loose.
Tank type electric water heaters can be set on or against any wood, carpet, plastic etc surface.
Electrical connections must be made inside electrically rated box or enclosure. No homemade boxes, covers etc. Hardwired heaters must be connected using 600 volt sheathed cable. No extension cords, unless plugged directly into outlet.
Cover all electrical boxes and connections with electrically rated cover that matches box. Cover must stay in place.
Electrical connections can be at top or on side.. Secure wire and conduit to structure.
Buy:
Earthquake straps 
Resources
See earthquake strap illustration  
TP valve code
Drip pan
Drip pan
6) Drip pan saves damage
Drip pan saves damage
Resource:
See drip pan installation
Buy:
Water heater drip pans 
Buy:
Water detectors 
Auto-shut-off valve 
7) TP overflow code
Overflow tube cannot be inserted inside drain line, capped off, or be terminated where it can cause damage if TP releases water.
Temperature-pressure relief valve is required for safe operation of water heater. DO NOT CAP OFF.
TP spews scalding water when internal temperature and pressures exceed safe limits. This prevents water heater explosion. Direct overflow tube to nearby drain or to outside.
Overflow tube must be as short as possible and same diameter as valve discharge connection. Do not downsize into smaller pipe. Overflow tube maximum 4 elbows and 30 feet length. Overflow must terminate 6" above drain or water line.
Ideal to vent TP directly outdoors ending in a downward pipe. Overflow pipe must pitch downward, and cannot be under water. TP valve can draw water back into water heater if end of overflow tube is under water. End of overflow tube cannot be threaded.
Gently open and close TP valve once each 1-3 years to make sure valve is functioning.
Resource
How to test, maintain, and replace TP valve
Solder copper pipes Soldering copper pipes?

Most under-counter 6 gallon and 12 gallon water heaters have 1/2" connections.

Avoid soldering directly to water heater.
First, solder piece of pipe to male or female adapter, and then attach adapter to water heater.
This will avoid direct torch heat on water heater.
Resource
How to solder copper pipes


8) Insulate pipes, and tank

Do NOT block TP valve lever
Electric water heater can be totally covered with insulation except TP valve
8a) Insulate top of TP valve
Do NOT block TP valve lever
Electric water heater can be totally covered with insulation except TP valve
Element burns out
Tank must be full of water
9) Tank MUST be full of water before applying power
Element will instantly burn out if tank is not full of water.

Fill tank completely until faucet is running full stream
THEN open TP valve momentarily to release last of air from top of tank.
Once tank is full of water, power can be turned ON.
Resources
How to test element

Finished install

Larger image
Showing side connections, electric conduit top of tank, drain pan and TP overflow tube going to floor drain. Allow 6" space between TP overflow tube and floor drain.
Or overflow tube can be directed outdoors
Does not show drain valve installed.
Under counter water heater
Larger image

Showing 120 volt plug and outlet for some models.
Do not use extension cord.
Outlet must have correct polarity and be grounded.
Check outlet with circuit analyze.
TP overflow tube has 6" space above floor drain.
Drip pan has overflow tube touching floor drain.

Resource
Basic House wiring
Troubleshoot and service guide
How to troubleshoot electric water heater

Point of use service manual
Bosch Ariston resources
How to maintain water heaters
Commercial point of use service manual

For tankless electric:
How to wire tankless electric water heater
Other manuals:

Hubble 2.5 gallon manual
Bradford White instantaneous
Emerson point of use
Insinkerator manuals
Boil water faucet- new product

Water heater manufacturers

Electricity to Under counter water heater


Never assume power is OFF
Use non-contact voltage tester on timer, on wire, on outlet to see if power is present.
Press button on tester, if single beep then no power is present. If continuous beep then power is present.
Never stand on bare ground, always stand on dry boards, do not hold or touch anything metal when working on timer or water heater that has power, tape tester leads to wood sticks, never touch wet water heater, or flooded water heater, or timer that had a short or fire without turning power OFF.

Buy:
Multimeters 
Buy non-contact voltage tester 
Electric testers
Test water heater
120Volt water heater
color-code household wire120 volt water heater has Black and white wire
Code says: use only approved 600 volt electrical wire. Do not use stranded wire for 14-12-10 gauge wiring. Use solid copper wire. Never use extension cord for permanent household wiring. Always connect ground wire. Make sure all connections are inside electrically rated enclosure with cover that fits.
Typical 12-2, 120Volt electrical line has Black Hot, White Neutral, and bare ground.
Connect black to black and white to white.
Ground wire must be connected to ground screw.
Join wires using twist on wire connector and twist very tight ... make sure all bare copper is covered.

Resources
How to twist wire and install wire connectors
How to drop wire from attic
Color code and wire rating
Put cover over all electrical connections.
Calculate electrical demand
1) Read label on side of water heater. Find watt and volt rating.
Watts divided by 120Volts = amperage
120Volt 1500 watt water heater consumes 12.2 amps.

2) Read label on dishwasher: Typical dishwasher consumes 6-11 amp at max draw.

3) Label circuit breaker that connects to dishwasher. Check other loads (lights, TV, etc) that are connected to same breaker. Add up total wattage of all items on breaker. Divide wattage by 120Volt to find total amp draw on breaker. Add 6-11 amps drawn by dishwasher to find total load.

4) Can you safely add another 12.2 amp water heater to the circuit?
Electrical capacity calculation:
1) 15 amp breaker with 14 gauge wire is recommended at 80% rated load = 12 amp load.
2) 20 amp breaker with 12 gauge wire is recommended at 80% rated load = 16 amp load.

3) Combined load for dishwasher and water heater is 18.5-22.3 Amps.
If you have 15 amp breaker or 20 amp breaker, then dishwasher and water heater should not be turned ON at same time.

Hubble 750-1000 watt 2-1/2 gallon with 1/4" male connections

1500 Watt 2-1/2 to 6 gallon


Typical 1500 watt 20 gallon

No wire available for 120 volt installation?
120 volt under counter water heater requires dedicated breaker that serves no other appliance.
What if you can't run another wire from the breaker box. No problem, split duty with the dishwasher, or microwave oven.
The water heater does not need power full time. Dishwasher is only used now and then. Use a switch or a timer to toggle between each load.
water heater circuitBuy:
Dishwashers 
How to toggle between under counter water heater and dishwasher

Same wiring for either 120 or 240 volt loads
Code permits 15 or 20 amp switch on a 20 amp breaker ... as long as switch is rated for same voltage and more amps than Load (anything that consumes power is Load).
Use only approved 600 volt, solid copper wire under screw terminals. Never use extension cord for permanent household wiring, unless plugged into outlet.
Hardwired water heaters can be wired to 12 gauge extension cord, then plugged into outlet ... do not use 14 gauge cord.


Objective: Either the dishwasher has power or the under-counter water heater has power. But neither at same time. Why? Because safe maximum amps on 20 amp breaker is 80% or 16 amps ... while dishwasher and water heater together consume 23 amps.
Do not install 30 amp circuit breaker unless wire is also increased in size from 12 ga to 10 gauge. Color code for wire

How to wire: Incoming wire from breaker has 2 wires. If voltage is 120, then the white Neutral wire is never switched on-off. Connect white Neutral wire to each appliance.
Black Hot wire is switched on-off. Connect Hot wire to COM terminal on the 3-way switch (dark or different color screw). Then run a Hot wire to each appliance from the other two screws on switched.

Heavier amp loads, or more voltage, such as 30 amp 240 volt water heater, use a 30 amp 3-way switch (safe max 23 amps).
Other options, for higher amperage loads and motor loads (such as irrigation pumps, shop tools etc), include using a switch (or timer) to toggle loads with 30-40 amp open frame relay.
For heavier amp loads, or 240 volt ...Buy:
Leviton 3033 switch 
30 amp 3-way switch
Resource:
How to wire open frame relay
water heater circuit Larger image
Toggle between under counter water heater and dishwasher using small timer
Small FM1 timer module is reliable, long lasting, and rated 15 amps.
Timer can be installed inside a small plastic enclosure, and then install box cover.
Buy 24 hour 120 volt
FM1STUZ/ 24-120-240 Volt  timer models
Larger imageFM-1 timer
Example wiring:

1) Buy plastic box with 3/4 Knockout. Or drill 1" hole.
2) Use 3/4" male adapter so all 3 wires enter box from same knock-out.
3) Attach timer with self-tapping screws.
4) Remove timer from box to connect terminal ends to timer
5) In this illustration, I trimmed the ground wires shorter and re-applied wire connector so all wires could fit into box before putting cover over box.
6) Attach box next to water heater. Make box accessible so times can be changed. Timer must be re-set to current time after power outage.
FM1 timer
Larger image
Wire 1500 watt water heater to FM1 timer
FM1 timer rated for 21 amps/ max 2000 watts
21 amp x 120volt = 2520 watt x 80% = 2016 watts

Buy: FM1 timer module/ 7-day or 24 hour
Intermatic/ Grasslin FM1 timers 
24-hour 14 minute 120Volt 60 Hz 
7-day 2 hour increments 120volt 60 Hz 
24-Hour 240Volt 60 Hz 
7-day 240Volt 60 Hz 
Timer toggle between applainces
Larger image
Toggle between 240 volt appliances:
Toggle between 30 amp clothes dryer and 30 amp water heater.
Toggle between 50 amp rang and 50 amp tankless water heater.

Toggle between 240 volt appliances:
Toggle between 30 amp clothes dryer and 30 amp water heater.
Toggle between 50 amp rang and 50 amp tankless water heater.

Choice of timers:
Tork TU and DTU
Intermatic GM40, GMQ, GM40AV, GM40AVE
Woods WiFi
GE Zwave
See all these timers together




Buy
Tools
Milwaukee
DEWALT
Black and Decker
Stanley
SKIL
Makita
Porter-Cable
Bosch

Irwin Hand tools
Klein hand tools
Fluke electrical testing
Dremel hobby tools

Campbell Hausfeld air powered
Tekton automotive

Powerbuilt automotive
Saws and saw blades

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