A.O. Smith R4MR-320E Signature 240-Volt 32-kW 2.8-GPM Tankless Electric Water Heater Use & care guide

Installa on Instruc ons and Use & Care Guide

Electric Tankless

Water Heater

PLEASE DO NOT RETURN THIS UNIT TO THE

STORE.

Read this manual and the labels on the water heater before you install, operate, or service it. If you have di culty following the direc ons, or

United States: 1-877-817-6750

Canada: 1-800-265-8520

We can help you with installation, operations, troubleshooting, or

maintenance. Before you call, write down the model and serial number from

on, opera on, or service can damage the water heater, your house and other property, and present risks including  re, scalding, electric shock, and explosion, causing serious injury or death.

Table of Contents ..............................Page

IMPORTANT SAFETY INFORMATION .............................2

GENERAL INFORMATION ...............................................5

INSTALLATION ...............................................................11

OPERATION ...................................................................15

TROUBLESHOOTING ....................................................17

SERVICE .........................................................................22

WIRING DIAGRAMS .....................................................29

APPENDIX ......................................................................34

ENTE R

°F

°C

ENTE R

°F

°C

Keep this manual near the water heater for future reference whenever maintenance, adjustment or service is required.

Retain your original receipt as proof of purchase.

0818

100306524_2000558984 (REV. B)

IMPORTANT SAFETY INFORMATION

Read and follow all safety messages and instruc ons in this manual.

This is the safety alert symbol. It is used to alert you to poten al physical injury hazards. Obey all safety messages that follow this symbol to avoid possible property damage, serious injury or death. Do not remove any permanent instruc ons, labels, or the data plate from either the outside of the water heater or on the inside of the access panels. Keep this manual near the water heater.

Important informa on to keep...

Fill out this sec on and keep this manual for reference.

Date Purchased:

Model number:

Serial number:

DANGER

WARNING

CAUTION

NOTICE

DANGER indicates hazardous situa on that, if not avoided, will result in death or serious injury.

WARNING indicates a hazardous situa on that, if not avoided, could result in death or serious injury.

CAUTION indicates a hazardous situa on that, if not avoided, could result in minor or moderate injury.

NOTICE indicates prac ces not related to physical injury.

Maintenance performed: Date:

T o reduce the risk of property damage, serious injury or death, read and follow the precau ons below, all labels on the water heater, and the safety messages and instruc ons throughout this manual.

General Requirements

unit in accordance with local codes, or in the absence of local codes, with the current edition of the National Electrical Code:

ANSI/NFPA 70 in the USA or

CSA standard C22.1 Canadian

Electrical Code, Part 1 in Canada.

heating, and air conditioning codes during installation.

RISKS DURING INSTALLATION

AND MAINTENANCE

WARNING

Electric Shock Risk

Contact with the electrical parts inside the water heater can result in severe injury or death from electrical shock:

Disconnect power by opening the circuit breaker(s) before installing or servicing.

SOME MODELS ARE CONNECTED

TO MORE THAN ONE BRANCH

CIRCUIT, AND MORE THAN ONE

DISCONNECT SWITCH MAY BE

REQUIRED TO DE ENERGIZE THE

EQUIPMENT. ALL BRANCH CIR

CUITS MUST BE DISCONNECTED

PRIOR TO SERVICE.

Be sure the cover is reinstalled and secured after servicing to reduce the risk of fire and electric shock.

RISKS DURING OPERATION

WARNING

Scalding Risk

This water heater can make water hot enough to cause severe burns instantly, resulting in severe injury or death. s howering.

install Thermostatic Mixing

Valves (temperature limiting valves) at each point of use.

These valves automatically mix hot and cold water to limit the temperature at the tap. Mixing valves are available at your local hardware store or from your plumbing supplier. Follow the installation and adjustment of the valves.

set point is factory set to 120°F to reduce the risk of scalding.

Exception: single chamber (pointof-use) models are factory set to approximately 105°F. the risk of scalding, but even at

120°F, hot water can scald. If you choose a higher temperature,

Thermostatic Mixing Valves located at each point of use are particularly important to help avoid scalding.

confirm that power is off before working on or near any electrical parts.

Temperature Time to Produce a

Serious Burn

120°F (49°C) More than 5 minutes

125°F (52°C) 1½ to 2 minutes

130°F (54°C) About 30 seconds

135°F (57°C) About 10 seconds

140°F (60°C) Less than 5 seconds

145°F (63°C) Less than 3 seconds

150°F (66°C) About 1½ seconds

155°F (68°C) About 1 second

For information about changing the factory temperature setting, refer to page 15.

Even if you set the water heater set point to a low se ng, higher temperatures may occur in certain circumstances: someone adjusted the temperature set point to a higher setting.

heater is pre-heated (for example, by another water heater), the temperature of the water may be higher than the temperature set point.

interface on two- or four-chamber models) or other malfunctions may result in higher than expected water temperatures.

To reduce the risk of unusually hot water reaching the  xtures in the house, install Thermosta c Mixing Valves at each point of use.

If anyone in your home is at par cular risk of scalding (for example, the elderly, children, or people with disabili-

es) or if there is a local code or state law requiring a certain water temperature at the hot water tap, then these

precau ons are par cularly important.

According to a na onal standard, American Society of Sanitary Engineering

(ASSE 1070), and most local plumbing set point should not be used as the sole means to regulate water temperature and avoid scalds.

Properly adjusted Thermosta c Mixing

Valves installed at each point of use set point to a higher se ng without increasing the risk of scalds. A higher temperature can help provide proper water temperatures for appliances such as dishwashers and washing machines. could cause a fire risk. If the water heater is subjected to flood conditions or has been submerged in water, the entire water heater must be replaced.

erly according to the instructions on page 13. Use a UL listed or CSA approved strain relief. Connect the ground wire to the ground lug. (The ground lug is identified by a green and white ground label inside the water heater.)

Water Contamination Risk

Do not use chemicals that could contaminate the potable water supply. Do not use piping that has been treated with chromates, boiler seal, or other chemicals.

WARNING

Fire Risk

To reduce the risk of a fire that could destroy your home and seriously injure or kill people: easily such as paper or clothes next to the water heater.

is in place. This cover keeps debris from entering and potentially being ignited, and helps keep any internal fires from spreading.

ing wet. Immediately shut the water heater off and have it inspected by a qualified person if you find that the wiring or control board have been exposed to water in any way

(e.g., leaks from plumbing or leaks from the water heater itself). Such leaks can damage property and

GENERAL INFORMATION

Introduction

necessary for the installation, operation, and maintenance of the water heater.

the rating plate which is attached to the side panel of the water heater.

instructions completely before installing this product.

or questions regarding this equipment, consult the manufacturer or its local representative.

This appliance is an on-demand, electric tankless water heater. It is designed to efficiently supply endless hot water for your needs.

A built-in alarm is included. If water leaks inside your electric water heater, an alarm will sound to provide warning. Simply turn off power to the water heater at the circuit breakers, turn off the water supply, then correct the leak.

Your water heater also includes on-board self diagnostics. If the system produces an error code, see following pages:

Component

Descriptions

Temperature and Pressure

Relief Valve

In most cases, you are not required to install a temperature and pressure relief valve (T&P valve). However, some local codes do require the installation of a T&P Valve. If a T&P valve must be installed, install it on the hot outlet pipe according to the local code.

If you install a T&P valve, turn on the water supply to ensure that no water drips from it. Next, operate the valve manually two or three times to purge the trapped air from the top of the valve. Verify that water has stopped flowing completely before connecting the discharge pipe to the valve.

NOTICE: If a temperature and pressure relief valve is installed, it must be piped by minimum 1 inch pipe to a suitable drain capable of discharging 10 GPM. A splash cover must be included to protect the area of attachment to the wall. The manufacturer will not be responsible for any water damage that may occur.

WARNING! Do not cap or plug the

T&P relief valve or discharge pipe.

Component Identification: Point-of-Use Models (RPV, CPV)

OUTLET INLET

Heating Element

(Behind inlet/outlet)

Thermistor* Connections

T-Aux Auxiliary thermistor

T-In Inlet thermistor

T-Out Outlet thermistor

T-Aux

T-In

T-Out

Outlet Thermistor *

(Connects to T-Out)

Auxiliary Thermistor *

(Connects to T-Aux)

Inlet Thermistor *

(Connects to T-In)

TERMINAL

BLOCK page 19.

POWER

SUPPLY

* Often referred to as a temperature sensor.

Continued on the next page...

Component Identification: Two-Chamber Models (R2V, C2V)

OUTLET INLET

HEATING ELEMENTS

NOTICE:

The user interface is described in Figure 7, page 16.

Intermediate

Thermistor *

(connects to

TH-1)

TH-1

TH-2

TH-IN


TH-IN Inlet thermistor

TH-1 Intermediate thermistor

TH-2 Outlet thermistor

Access Plate

(for draining)

L1

L2


Outlet Thermistor *

(connects to TH-2)

Inlet Thermistor *

(connects to TH-IN)

Component Identification: Four-Chamber Models (R4L, C4L, R4M, C4M)

OUTLET Intermediate

Thermistor *

(connects to

TH-2)

Element Element

Intermediate

Thermistor *

(connects to

TH-1)

Element Element

NOTICE:

The user interface is described in Figure 7, page 16.

INLET

TH-1

TH-2

TH-3

TH-4

TH-IN


TH-IN Inlet thermistor.






Outlet Thermistor *

May be located on outlet elbow.

(connects to TH-4)

L1

L2

L1

L2

Access Plates

(for draining)

Intermediate Thermistor *

(connects to TH-3)

Inlet Thermistor *

(connects to TH-IN)

General Specifications

Models

Point-of-Use:

RPV, CPV

Two Chamber:

R2V, C2V

Four Chamber:

R4L, C4L, R4M, C4M

Wiring & Circuit Breaker

Requirements

Water Connections

Weight lbs. (kg)

Water Heater

Dimensions*

8 lbs. (3.6 kg) 13 lbs. (5.9 kg) 20 lbs. (9 kg)

(H 42.2cm x W 16.5cm x D 18.3 cm) (H 45.1 cm x W 29.2 cm x D 15.6 cm) (H 46 cm x W 43.2 cm x D 15.6 cm)

* Height dimension includes the distance from the bottom of the heater to the highest point of the inlet/outlet.

Width dimension includes the mounting tabs on the left-hand and right-hand sides (two- and four-chamber models).

NOTE: without incurring obligations. reducing valve with a bypass should be installed in the cold water inlet line.

Electrical Requirements

Follow these steps to determine the electrical requirements for your water heater:

2.) Locate that model number in one of the tables listed below.

For example, if your model is RPVA-24-K , find *P**-24-K in the appropriate table.

Models within each table are sorted by Voltage first, then by Wattage per Element (KW) .

Follow the requirements listed for your model.

Point-of-use models are listed below.

Two-chamber models: page 9.

Four-chamber models: page 10.

Use copper conductors only.

Model

Point-of-Use Models

(For potable water heating only. Not for space heating.)

NOTICE: Models sorted by Voltage , then by Wattage per Element .

Recommended

Breaker Size

(Amps)

Voltage Number of

Elements

Wattage per Element

(KW)

Current per

Breaker

(Amps)

Recommended

Wire Size

(AWG)

*

20 120 1 2.4

20.00

12

25 120 1 3 25.00

10

*P**-24-K

*P**-30-K

*P**-35-K

*P**-40-X

*P**-78-X

*P**-35-E

30

20

40

15

120

208

208

1

1

1

1 240

*P**-45-E 20 240 1

*P**-55-E 25 240 1

*P**-70-E 30 240 1

*P**-80-E 40 240 1

*P**-90-E 40 240 1

*P**-120-E 50 240 1

*P**-30-Y 15 277 1

* All wiring/conductors must be rated for 90°C or greater.

3.5

4

7.8

3.5

4.5

5.5

7

8

9

12

3

29.17

19.23

37.5

14.58

18.75

22.92

29.17

33.33

37.50

50

10.83

10

12

8

14

12

10

10

8

8

6

14

Element Type

Single

Single

Single

Dual

Single

Single

Single

Single

Single

Single

Single

Single

Single

Follow all code requirements.

Model

Point-of-Use Models



Recommended

Breaker Size

(Amps)

Voltage Number of

Elements

Wattage per Element

(KW)

Current per

Breaker

(Amps)

Recommended

Wire Size *

(AWG)

15 277 1 4 14.44

14 *P**-40-Y

*P**-60-Y 25 277 1

*P**-73-Y 30 277 1

*P**-90-Y 40 277 1


6

7.3

9

21.66

26.35

32.49

10

10

8

Element Type

Single

Single

Single

Single

Follow all code requirements.

Model

Two-Chamber Models



Recommended

Breaker Size

(Amps)

Voltage Number of

Elements

Wattage per

Element (KW)

Current per

Breaker

(Amps)

Recommended

Wire Size *

(AWG)

*2**-140-X

40 amps each

(2 circuits)

*2**-120-E

60 amps

208

240

2

2

7

6.1

33.65

50.83

8

6

*2**-140-E

60 amps

*2**-160-E

40 amps each

(2 circuits)

*2**-180-E

40 amps each

(2 circuits)

240

240

240

2

2

2

7

8

9

58.34

33.33

37.5

6

8

8


Element

Type

Single

Single

Single

Single

Single

Model

*4**-280-X

*4**-180-E

*4**-220-E

*4**-240-E

*4**-280-E

*4**-320-E

Four-Chamber Models (Single Phase)

For potable water heating only. Not for space heating.


Recommended

Breaker Size

(Amps)

Voltage Number of

Elements

Wattage per

Element (KW)

Current per

Breaker

(Amps)

Recommended

Wire Size *

(AWG)

70 amps each

(2 cirucits)

40 amps each

(2 circuits)

50 amps each

(2 circuits)

60 amps each

(2 circuits)

60 amps each

(2 circuits)

70 amps each

(2 circuits)

208

240

240

240

240

240

4

4

4

4

4

4

7

4.5

5.5

6

7

8

67.31

37.50

45.83

50.00

58.33

66.67

6

6

6

6

8

6


Element

Type

Single

Single

Single

Single

Single

Single

INSTALLATION

Getting Started

Clearances

See Figure 1 or Figure 2.

Top Clearance: A minimum of 12 inches (30.5 cm) is required for removal and maintenance of heating elements and to provide access for plumbing connections.

Side Clearance: Allow an 8 inch (20.3 cm) minimum horizontal space for the heater. This horizontal clearance will allow for the removal of protective cover screws and provide access to

Figure 1.

Wall

Side View

Front Clearance:

15 + (38.1 cm +)

12

(30.5 cm)

2-Chamber or

4-Chamber

Water Heater electrical wires that will enter the heater from the side.

Bottom Clearance: At a minimum, maintain a bottom clearance of 8 inches (20.3 cm) for single chamber models or 15 inches (38.1 cm) for 2- or

4-chamber models. Do not store any items underneath the water heater.

Front Clearance: Maintain a minimum clearance of 8 inches (20.3 cm). In the absence of a door or removable access panel in front of the heater, allow a minimum of 15 inches (38.1 cm) front clearance. This will allow for cover removal and ease of service. See

Figure 1 or Figure 2.

Front

View

Wall or adjacent object

Code Compliance

unit in accordance with local codes, or in the absence of local codes, with the current edition of the National Electrical Code:

ANSI/NFPA 70 in the USA or

CSA standard C22.1 Canadian

Electrical Code, Part 1 in Canada.

plumbing, heating, and air conditioning codes during installation.

Install one each corner.

Figure 2.

Wall

Side View

8

(20.3 cm)

12

(30.5 cm)

Single

Chamber

Water Heater

Front

View

8

(20.3 cm)

ENT ER

°F

°C

8

(20.3 cm)

Minimum Clearances

(

15+

+)

8

(20.3 cm)

Front Clearance:

15 + (38.1 cm +)

NOTICE: Point-of-use models may be mounted horizontally. See Figure 3, page 12.

8+

(20.3 cm +) inlet/outlet.)

Minimum Clearances

Wall or adjacent object be installed indoors only.

clean, dry area that is as close to the point of use as possible. Do not install it in a bath enclosure or shower stall. must be protected from freezing.

Do not install your water heater where it may be subjected to freezing temperatures.

to dampness, high humidity, moisture, or dust. Such locations include crawl space under a house or building, in the garage (in regions prone to high humidity) and in the attic (unless the attic has been converted to a living space). will not be accessible to children.

WARNING! This water heater can make water hot enough to cause severe burns instantly, resulting in severe injury or death. is accessible and that minimum

clearances are observed. Do not store any items underneath the water heater, and do not store flammable liquids or other flammable materials near the water heater. This is important for safety and future service. See underneath condensate lines. protection against water damage, is recommended to be installed under the water heater in case of leaks. In addition, you may install an active water leak detector with a shutoff valve which can turn off the water supply in the event of a leak. The manufacturer is not responsible for damage due to water leaks.

1. Unpack the heater from the shipping carton, but do not cut the shipping carton with a sharp instrument.

2. Stand the unit upright and remove the plastic wrap.

3. Remove the screws that secure the protective cover.

4. Remove the cover. If your water heater has a user interface display

(UIM) , unplug its ribbon cable from the control board in the water heater. (A UIM is shown in

Figure 7, page 16.)

NOTICE: Be sure to remember where to plug it back in later.

When the me comes to plug the connector back into the control board, it must be oriented correctly. We recommend marking the connector and board with a marker. You will then be able to align the marks later. See also

Figure 5, page 14.

5. If you have a point-of-use model, locate the four mounting holes in the back plate. (If you have a two- or four-chamber model, there are two mounting tabs on each side of your water heater.)

6. Two- or four-chamber water heaters only:

Apply one stando bumper to each corner on the back of the water heater. Stando s are provided. These stando s must be installed so the water heater can vent properly.

See Figure 1, page 11.

7. Determine the mounting location on the wall, then verify your page 11.)

8. Position the unit against the wall.

Make sure that the unit is level.

NOTICE: Two-chamber and four-chamber models must be oriented with the inlet and outlet facing upward. However, point-of-use (POU) models may be oriented horizontally as described in Figure 3. To mount a POU water heater horizontally, follow the instructions on page

34.

9. Secure the water heater to the wall or other suitable structure with screws, bolts, or anchors as appropriate. Ensure that the mounting surface and fasteners will support the weight of the water heater. (You will reinstall cover later.)

Figure 3.

water heater:

Horizontal

3

Connect the

Water Lines

NOTICE:

DO NOT apply heat to the water lines, nipples, or any fitting on the water heater. Heat from soldering may damage the heat exchanger.

tape) is the only sealer that may be used on the threads of the inlet and outlet fittings. DO

NOT use pipe dope or PVC/CPVC primer and glue on the threads of the inlet and outlet fittings.

Exposure to these compounds will damage the nipples, causing leaks. the hot and cold water lines to

the heater. The second wrench must be used fittings securely because they are designed to turn freely.

are recommended for your installation. with this water heater. Do not introduce pool or spa water, or any chemically treated water into the water heater.

regenerated water softener or a water supply of salt water.

damage caused by water quality.

pressure: 50 to 60 psi. Higher pressures require a pressure reducing valve. an attic require a bleed air separator.

be installed where water hammer exists.

NOTICE: Do not supply electrical power to your water heater yet. If you do so at this point, you will damage your heating element(s).

1. Make sure that the water supply is turned off.

2. Connect the hot water line to the hot outlet of the water heater.

(Figure 4.)

3. Connect the cold water line to the cold inlet of the water heater.

(Figure 4.)

4. Open the valve on the main water line to supply water to the heater.

5. Open several hot water fixtures and allow water to run through the water heater for several minutes to purge air from the water lines.

6. Check for water leaks. Correct any that are found.

7. If you installed a T&P valve to meet local code requirements, operate it manually several times to allow any trapped air to escape.

NOTICE: Failure to purge air from the water lines can leave air pockets, causing damage to the heating elements when power is applied.

Figure 4 .

WARNING

Failure to observe these warnings could lead to an improper installation, and the risks include fire, electrical shock, and/or death:

Installation must be performed by a qualified installer. The installer (licensed professional) is responsible for the correct installation of the water heater and for compliance with all national, state / provincial, and local codes.

Refer to the electrical requirements and electrical schematic during installation and service.

Turn off power service at the main circuit breaker(s) prior to installation. Working on an energized circuit can result in severe injury or death from electrical shock.

Some models must be connected to more than one branch circuit, and more than one disconnect switch may be required to de-energize the equipment. All branch circuits must be disconnected during installa on or service.

Install and properly ground the unit in accordance with local codes, or in the absence of local codes, with the current edition of the National Electrical Code:

ANSI/NFPA 70 in the USA or CSA standard C22.1 Canadian Electrical

Code, Part 1 in Canada.

NOTICE:

When using stranded wire, make sure that all strands are secure inside the terminal block. A loose strand can cause a short circuit and damage the circuit board.

1. Be sure the electrical power to the water heater is turned OFF at the circuit breaker panel (or

2. Using a non-contact circuit tester, check the wiring to make certain the power is OFF.

ng plate and ensure that the electrical

(ampacity) and circuit breaker ra ng/type are correct for this water heater.

NOTICE: The electrical requirements for your model are which starts on page 8.

4. Connect the electrical service as described in

(starting on page

8).

There is a wiring diagram label on manual.

5. Do the following:

Check all electrical connections to make sure that they are correct and secure.

Make sure that the supply voltage, wiring size (ampacity), circuit breaker rating and type are on page 8).

Label all breakers/connections to the water heater.

6. Ensure that all air has been purged from the water lines by opening several hot water fixtures near the water heater. Run water through the water heater until all air is purged from the lines.

7. Two- and four-chamber models only: Plug the connector end the control board. See Figure 5.

(Plug it in where you see two rows of header pins close together, five pins in each row.) If necessary, in the wiring diagram for your page 29.)

If you marked the board and connector during earlier steps, align the marks when plugging the connector in.

NOTICE: The plug must be oriented correctly. If you plug it in backwards, it will not cause damage, but the display will not work.

If the display does not work a er you have completed installa on, follow these steps:

A.) Disconnect power at all branch circuits.

B.) Disconnect the plug.

C.) Rotate the plug 180 degrees, then plug it back in.

Operating instructions are listed on page 15.

5

Test Water

Heater Operation

1. At nearby hot water faucets, turn water on medium-low.

You may hear a hissing or crackling noise from the heat exchanger after the unit begins to heat water. This is normal.

2. Check water at the fixtures to make sure that the water is being heated.

NOTICE:

Your water heater includes on-board self diagnos cs. If an error occurs, the

fy more informa on (page 17 or 19).

WARNING! Be sure the cover is secured to reduce the risk of  re and electric shock.

9. Turn on power to the water heater.

10. Verify proper operation.

Figure 5.

Ribbon Cable

Two- and four-chamber models only:

Red Band

on Board

Ribbon Cable

Connector

Control Board

NOTICE:

When plugging the display

(User Interface Module) into the control board, orient it as shown in this graphic.

OPERATION

Water Temperature

Adjustment

WARNING

Scalding Risk

This water heater can make water hot enough to cause severe burns instantly, resulting in severe injury or death. Before a emp ng to adjust the temperature instruc ons are not clear, contact a quali  ed service technician.

To adjust your temperature se ng, refer to one of the following procedures.

Point -of-use models only:

To adjust the temperature setting, turn the temperature adjustment knob as described below. This knob can be found at the top of the circuit board next to the plumbing connec-

ons. (Figure 6.)

The factory se ng is approximately

105°F (+/-1°F). turn the knob to the left (counter clockwise).

turn the knob to the right

(clockwise).

to turn the knob.

The water temperature set point can be adjusted within a range of 90°F

(32C) and 140°F (60 °C).

Two- or four-chamber models only:

The water temperature set point can be adjusted within a range of 90°F

(32C) and 140°F (60 °C).

To change the set temperature,

1. Press and release either the

UP or DOWN button (Figure 7, page 16). The display will blink and allow you to adjust the temperature set point.

2. Press and hold the UP or

DOWN button to scroll through the temperatures quickly.

Single presses will adjust the temperature setting one degree at a time.

3. Press the ENTER button to confirm.


Figure 6.

POINT-OF-USE MODELS ONLY:

TEMPERATURE ADJUSTMENT KNOB ON INTERNAL CIRCUIT BOARD

PLUMBING CONNECTIONS

BEHIND CIRCUIT BOARD

TEMPERATURE ADJUSTMENT KNOB

TURN KNOB TOWARD LEFT

(COUNTER-CLOCKWISE )

TURN KNOB TOWARD RIGHT

(CLOCKWISE )

SCREWDRIVER.

To toggle between Fahrenheit and

Celsius,

1. Press and hold the DOWN button for five seconds. See Figure 7.

2. The °F or °C LED will illuminate, and the 7-segment LED will display the temperature set point in the appropriate units.

Figure 7 .

Two and Four Chamber Models Only:

°C

En on

ENTER

TROUBLESHOOTING

Error Codes for Point-of-Use Models

If you have a two- or four-chamber model, see page 19.

WARNING

Electric Shock Risk


Disconnect power by opening the circuit breaker(s) or removing the fuses before installing or servicing.

Some models are connected to more than one branch circuit, and more than one disconnect switch may be

required to de-energize the equipment. All branch circuits must be disconnected prior to service.

The LED on the circuit board will display an error code as a  ash pa ern. The  ash pa ern is displayed as follows:

 rst digit of the error code is  ashed in RED .

GREEN  ash separates the  rst and second digits.

 ashed in RED .

See the example below. Components are iden  ed in Figure 8, page 18.

Example from the Table Below:

Flash Code Sequence: 3-6 (Freeze Warning). The 3-6 code would be displayed like this:

3

3 red  

6

 ashes

A er you iden fy the code, locate its descrip on and solu on in the table.

NOTICE:

ple codes; verify all sequences.

ple error codes, the LED will pause between each one. The GREEN LED will  ash twice a er the last error code. The error codes will then repeat. hear the  ash code, press the mode bu on for two seconds. This will turn the audible beeper on. See Figure 8, page 18.

Flash Code

Sequence

1-1

1-2

1-3

1-7

Description

Disable switch open (hardware jumper is not installed on the circuit board).

T-In thermistor is open.

T-Out thermistor is open.

Water temperature above 145°F has been detected. ( This code will clear when the condi on is corrected.)

Action / Solution

Install the missing jumper(s) on the circuit board as shown in Figure 8, page 18.

Both jumpers must be in place.

Check wiring. Replace as necessary.

Check wiring. Replace as necessary.

1. Turn o all power to the water heater. Open a nearby hot water  xture and allow water to run through the heater for about 5 minutes. Check the resistance of the temperature sensors (thermistors). If one of the thermistors has a resistance that is much higher than the others, replace that thermistor.

2. If the issue persists, the circuit board (control board) may need to be replaced.

Contact Technical Support.


Flash Code

Sequence

1-8

2-1

3-4

3-6

Description Action / Solution

Leak detected.

Tank is not full of water.

Cri cal error (displayed when other errors are triggered)

Freeze Warning (T-In thermistor detects that incoming water is lower than 40°F). This error may also occur when an open thermistor is detected.

Shut o all power to the water heater. Check for water leaks. Correct any leaks found. Dry the leak sensor (Figure 8), then dry the circuit board completely before restoring power.

Ensure that the heater is  lled with water and that there is no air trapped inside.

Make sure that the back  ow preventer or check valve is opera ng properly and is

 lled and there are no leaks, connect level detect spades on the circuit board to ground. If the code is accompanied by a clicking sound that is present when water is running, check the elements.

Follow the Ac on/Solu on for the other errors that are displayed.

1. Check wiring to the T-In thermistor. Ensure that the T-In thermistor is not faulty.

2. If incoming water is below 40°F, Turn o power to the water heater, close o its water supply, then drain the water heater. Wait un l the incoming water is above 40°F, then restore service.

Figure 8 .

LEAK SENSOR

OPEN PINS (3) REQUIRED JUMPERS (2)

BACK OF CASE

LED STATUS LAMP

INTERNAL CIRCUIT BOARD

PLUMBING CONNECTIONS

BEHIND CIRCUIT BOARD

TOP OF INTERNAL CIRCUIT BOARD

MODE BUTTON:

(PRESS FOR TWO

SECONDS TO TURN

AUDIBLE BEEPER

ON)

Error Codes for Two and Four Chamber Models

If you have a point-of-use model, see page 17.

WARNING

Electric Shock Risk


Disconnect power by opening the circuit breaker(s) or removing the fuses before installing or servicing.

Some models are connected to more than one branch circuit, and more than one disconnect switch may be

required to de-energize the equipment. All branch circuits must be disconnected prior to service.

Display

E02

E03

E04

E06

E10

E11

E12

E13

Description

Hardware determined that the heated water has exceeded the temperature limit.

Low water level in heater.

Action / Solution

Turn o power to the water heater. Contact Technical Support.

1. Turn off power to the water heater.

2. Turn on a nearby hot water faucet to flush air out of the water line.

3. When water runs uninterrupted from the hot water fixture, turn on power to the water heater.

Moisture/leak detected in heater. Turn o power and water supply to the water heater.


So ware determined that the water temperature is too high.

This error may appear when the unit is powered up. Turn on a hot water tap to run water through the water heater. The error should clear. If not, turn o the power to the water heater. Contact Technical Support.

Inlet temperature sensor is open.

Open thermistor.

2- and

4-Chamber models:

TH-1 open.

Point-of-use models:

T-Out open.

Open thermistor.

2-Chamber models:

Outlet thermistor open.

4-Chamber models:

TH-3 thermistor open.

4-Chamber models only:

TH-2 thermistor is open.

1. Turn o power to the water heater.

2. Check the connec ons of the thermistor in ques on.

3. Disconnect the thermistor, then reconnect it.


5. Does the error code reoccur? If yes, turn o power and replace the thermistor that is listed in the le


E23

E24

E51

&

E52

Display

E14

E20

E21

E22

Description


Outlet thermistor open (TH-4).

Action / Solution

1. Turn o power to the water heater.

2. Check the connec ons of the thermistor in ques on.

3. Disconnect the thermistor, then reconnect it.


5. Does the error code reoccur? If yes, turn o power and replace the thermistor that is listed in the le

Inlet thermistor shorted.

Shorted thermistor.

2- and

4-Chamber models:

TH-1 shorted.


T-Out shorted.

2-Chamber models:

TH-2 thermistor is shorted.

4-Chamber models:






Communica ons Failure. The user interface has lost connec on with the control board.

Replace the temperature sensor that is listed in the le -hand column.

Turn o power to the water heater. Contact Technical Support.

General Troubleshooting

The following chart provides an overview of basic troubleshooting.

Symptom

water is being used.

Hot water supply is warm, but it does not get hot.

Hot water supply is cold.

Hot water temperature fluctuates.

Possible Cause

Cold water used causes reverse flow through water heater.

Unit has been in standby for an extended period with no hot water use.

Temperature set point too low.

Flow is too high.*

One of the main circuit breakers may be tripped. (For units with more than one branch circuit only.)

Failed heating element or temperature sensor.

Flow is too high.*

The circuit breaker(s) may be tripped.


Control board failure.

Flow is too high*

One of the main circuit breakers may be tripped. (For units with more than one branch circuit only.)


Corrective Action

Install check valve on outlet.

NORMAL OPERATION. Unit will activate as needed to maintain a reference temperature to ensure quick start-up on next use.

Increase the temperature set point.

Reduce flow.

Check power panel. Reset breaker if tripped.

Replace element or sensor

(thermistor).

Reduce flow.



(thermistor).


Reduce flow.



(thermistor).

* If your water heater runs out of hot water too quickly, it may be too small for your needs. Consider replacing it with a larger model or adding additional heater(s) to meet flow demand. Please refer to the product specification sheet for proper flow rates based on incoming water temperature.

SERVICE

WARNING!

Electric Shock Risk

Servicing should be performed on this water heater only after it has been disconnected from the power supply circuit(s). Failure to do so can result in severe injury or death from electrical shock: circuit breaker or removing the fuses before installing or servicing.

more than one branch circuit, and more than one disconnect switch may be required to de-energize the equipment. disconnected prior to service. confirm that power is off before working on or near any electrical parts.

after servicing to reduce the risk of fire and electric shock.

Element Removal and

Replacement

WARNING!

Working on an energized circuit can result in severe injury or death from electrical shock. Turn power off.

Some models are connected to more than one branch circuit.

Disconnect all branch circuits before servicing unit.

Check wires with a non-contact circuit tester to make sure power is o . When you are  nished, be sure all covers are secured to reduce the risk of  re and electric shock.

Figure 9: Non-Contact circuit tester

If you are not comfortable replacing a hea ng element yourself, have this work done by a quali  ed person. To replace the hea the following tools and supplies:

NOTICE:

A built-in alarm is also included. If water leaks inside your electric water heater, an alarm will sound to provide warning. Simply turn off power to the water heater at the circuit breakers, turn off the water supply, then correct the leak. use models) point-of-use models only) adjustable wrench (for element removal; two- and four-chamber models)

1

plate for the correct wattage and voltage. Verify that your new heating element has the correct wattage rating and is sized correctly for your water heater.

Figure 10: Heating elements

2

Figure 11: Installed heating element

Con  rm that power is o by checking the wires with a non-contact circuit tester.

3

4

Open a nearby hot water faucet and run the water until it is cool.

WARNING! To reduce the risk of scalding, be sure the water runs cool before you proceed.

Close the inlet valve to the water heater , but leave the hot water faucet open to relieve pressure.

Con nued...

5

cover, then place a bucket under the water heater to catch any water that spills.

NOTICE: If you have a two- or four-chamber model, you must cable from the control board.

When you plug it back in later, it must be oriented correctly.

(See Figure 5, page 14.)

We recommend marking the connector and board with a marker. You will then be able to align the marks.

If you have a point-of-use water heater, go to step 6.

If you have a two- or four-chamber water heater, go to step 7 on page

24.

6

Point-of-use water heaters only:

6.1

A.) Remove both screws which secure the top plate to the water heater.

(See Figure 12.)

B.) Lift and remove the top plate.

Figure 12.

Top View of Point-of-Use Model

Top Plate Screws

Figure 13.


Grommet Orienta on

Outlet Inlet

Grommets

6.3. Remove the old element:

A.) Slide the inlet and outlet grommets upward to provide clearance. (Figure 13).

B.) Remove the screws that secure the red and black wires to the top of the heating element. (Use the

Phillips screwdriver. Save both screws for later use.)

C.) Disconnect the green ground wire from the heating element. (See

Figure 14.) It is secured with a spade connector. Pull it straight up from the element to slide it off the terminal.

Figure 1 4.

Element in point-of-use heater

Retaining Nut

Ground wire (spade connector)

D.) Unscrew and remove the retaining nut that secures the heating element (See Figure 14).

Use an adjustable wrench. You may also purchase an element replacement kit which includes a thin-walled socket. Call Technical

Support for ordering information.

NOTICE: During the next step, protect the circuit board from dripping water!

E.) Lift the element out of the water heater. NOTICE: As you lift the element out of the opening, wrap it with a rag to keep water from dripping onto the circuit board.

F.) Remove the brass ground ring from the top of the element. (See

Figure 15: Brass ring and flag terminal.) Set it aside for later use.

Figure 15: Brass ring and flag terminal

Flag terminal

Brass ground ring

(point-of-use models)

6.4 Install the new element:

NOTICE: Ensure that there is an O-ring installed above the threads of the element. (See Figure 20, page 25.)

A.) Insert the new element into its water heater opening.

B.) Place the brass ground ring on top of the element. Make sure that the flag terminal is positioned so that the ground wire can be reconnected easily (Figure 16.)

Con nued...

C.) Secure the element by installing and tightening the retaining nut (Figure

14, page 23). Do not overtighten.

D.) Secure the red and black wires onto the top of the heating element. Use the two screws that you removed earlier.

E.) Reconnect the green ground wire

(flag terminal).

6.5 Reassemble the point-of-use water heater:

A.) Reposition both grommets as shown in Figure 17. Ensure that their flat surfaces press firmly against the top plate when you reinstall it.

Figure 16.

Brass ring on point-of-use models.

B.) Reinstall the top plate and secure it with the two screws that you removed earlier. (See Figure 12, page 23.)

C.) Go to step 8 on page 25.

Figure 17.


Grommet Orienta on

Outlet

Flat

Inlet

Grommets

Flat surface presses against inside surface of housing. See above.

Place brass ground ring on top of element.

accessible.

7

Two- or four-chamber water heaters only:

7.1 Drain the two- or four-chamber water heater:

A.) Remove all six screws that secure the access plate beneath the element (at the bottom of the water heater). See Figure 18.

B.) Remove the access plate and allow the water to drain into the bucket.

C.) Clean the access plate and both seals.

D.) Make sure that both seals are seated properly, then reinstall the access plate. (Use all six screws that you removed earlier.)

Figure 18.

Access Plates:

Two- or Four-Chamber models only one access plate two access plates

7.2 Remove the old element:

A.) Remove the screws that secure the red and black wires to the top of the heating element (Figure 19).

Use the Phillips screwdriver. Save both screws for later use.

B.) Remove the heating element with an element wrench.

C.) Lift the element out of the water heater. NOTICE: As you lift the element and O-ring out of the opening, wrap them with a rag to keep water from dripping onto the circuit board.

Figure 19.

Top view of element

(two- or four-chamber model)

D.)

7.3 Install the new element:

A.) Insert the new element into its water heater opening. Make sure that the O-ring is positioned properly. (See Figure 20.)

Figure 20.

O-ring

B.) Tighten the element with an element wrench until it is snug, then tighten for 1/4 turn more.

C.) Secure the red and black wires onto the top of the heating element. Use the two screws that you removed earlier. Proceed to step 8.

8

Turn on the WATER supply to the heater.

9

Turn on a nearby hot water faucet to fill the heater with water.

Continue until all air has been expelled from the heater and pipes. If a

T&P valve is installed, operate it manually several times to allow any trapped air to escape.

10

Check for water leaks. Correct any leaks that are found.

NOTICE: Do not restore power until the circuit board and components are completely dry. If water has dripped anywhere inside the heater (during element replacement or leak check), dry it with a hair dryer or compressed air. Be sure to dry behind the circuit board.

11

If there are no water leaks, complete these steps:

A.) Two- or four-chamber water heaters only: Take the connector and plug it into the control board.

(Plug it in where you see two rows of header pins close together, five pins in each row.) If necessary, in the wiring diagram for your page 29.)

NOTICE: The plug must be oriented correctly. (The correct orienta on is shown in Figure 5, page 14.)

If you plug it in backwards, it will not cause damage, but the display will not work. If the display does not work a er you have completed installa on, 1.) disconnect power at all branch circuits, 2.) disconnect the plug, 3.) rotate it 180-degrees, then 4.) plug it back in.

WARNING! Be sure the cover is reinstalled and secured to reduce the risk of fire and electric shock.

C.) Restore power to the water heater.

D.) Run hot water from a faucet to make sure that the water heater is working as expected.

Thermistor

(Temperature Sensor)

Replacement

WARNING!





If you are not comfortable replacing a thermistor yourself, have this work done by a quali  ed person. To replace tools/supplies:

1

2

3

Locate the thermistor (temperature sensor) that was iden  ed by the error code.

Refer to the appropriate

 gure on page 26.

Figure 21.

4

Turn o power to the water heater.

Drain the water heater as described in the draining instructions (page 27).

from the control board.

Continued on page 27.

Figure 22.

Thermistor loca ons

(Point-of-use models)


T-Aux Auxiliary thermistor

T-In Inlet thermistor

T-Out Outlet thermistor

T-Aux **

T-In **

T-Out

OUTLET INLET

Outlet Thermistor *

(Connects to T-Out)

Auxiliary Thermistor *

(Connects to T-Aux)

Inlet Thermistor *

(Connects to T-In)


** If the inlet thermistor fails, there is no need to replace it.

Simply switch the

T-Aux and T-In plugs on the control board.

POWER

SUPPLY

TERMINAL

BLOCK

NOTICE:

Appearance of cap may vary.

Figure 23.

Thermistor loca ons

(Two-chamber models)

OUTLET

HEATING ELEMENTS

INLET

Intermediate

Thermistor *

(connects to

TH-1)

TH-1

TH-2

TH-IN

L1

L2

Figure 24.

Thermistor loca ons (Four-chamber models)

OUTLET Intermediate

Thermistor *

(connects to

TH-2)

Intermediate

Thermistor *

(connects to

TH-1)

INLET

TH-1

TH-2

TH-3

TH-4

TH-IN

L1

L2

L1

L2

Outlet Thermistor *

May be located on outlet elbow.

(connects to TH-4)

Intermediate Thermistor *

(connects to TH-3)








Inlet Thermistor *

(connects to TH-IN)

Outlet Thermistor *

(connects to TH-2)

Inlet Thermistor *

(connects to TH-IN)






5

Remove the thermistor by turning it counter-clockwise with a 1/2-inch open end wrench.

6

Install the new thermistor in the opening by turning it clockwise with a 1/2-inch open end wrench.

Make sure that the O-ring is in place before you install the thermistor.

Tighten the thermistor hand tight, then carefully tighten it with a wrench until it is seated. Do not overtighten.

7

into the control board. The proper loca on is shown in one of the

 gures on page 26.

8

Return the water heater to service. To do so, follow the

Draining the Water

Heater

WARNING!





Draining the Water Heater

1

Con  rm that power is o by checking the wires with a non-contact circuit tester.

2

3

Open a nearby hot water faucet and run the water until it is cool.

WARNING! Be sure the water runs cool before draining the water heater to reduce the risk of scalding.

Close the inlet valve to the water heater , but leave the hot water faucet open to relieve pressure.

4

then place a bucket under the water heater to catch any water that spills.

NOTICE: If you have a two- or fourchamber model, you must unplug the board. When you plug it back in later, it must be oriented correctly. We recommend marking the connector and board with a marker. You will then be able to align the marks. See also

Figure 5, page 14.

If you have a point-of-use water heater, go to step 5.

If you have a two- or four-chamber water heater, go to step 6.

5

Point-of-use water heaters only:

Drain the point-of-use water heater:

A.) Remove both screws which secure the top plate to the water heater.

(See Figure 25.)

Figure 25.

Top View of Point-of-Use Model

Top Plate Screws

B.) Lift and remove the top plate.

(Removing it will protect if from damage.)

C.) Cover the top of the water heater with heavy towels (to prevent water from dripping through the openings).

A er the towels are in place, disconnect the inlet and outlet water lines from the water heater.

D.) Remove the hea ng element as

E.) Insert a pump hose into the water the water out.

F.) Reinstall the hea ng element as described in

G.) Reinstall the inlet and outlet water lines to the water heater.

H.) Go to step 7.

6

Two- or four-chamber water heaters only:

Drain the two- or four-chamber water heater:

A.) Remove all six screws that secure the access plate beneath the element (at the bottom of the water heater). See Figure 26.

B.) Remove the access plate and allow the water to drain into the bucket.

C.) Clean the access plate and both seals.

D.) Make sure that both seals are seated properly, then reinstall the access plate. (Use all six screws that you removed earlier.)

E.) Repeat steps A through D for each access plate.

F.) Go to step 7.

Figure 26.

Access Plates:

Two- or Four-Chamber models only one access plate two access plates

Returning the Water Heater to

Service

7

When you are ready to return the water heater to service, turn on the WATER supply to the heater.

8

Turn on a nearby hot water faucet to fill the heater with water.

Continue until all air has been expelled from the heater and pipes. If a

T&P valve is installed, operate it manually several times to allow any trapped air to escape.

9

Check for water leaks. Correct any leaks that are found.

NOTICE: Do not restore power until the circuit board and components are completely dry. If water has dripped anywhere inside the heater, dry it with a hair dryer or compressed air. Be sure to dry behind the circuit board.

10

If there are no water leaks, complete these steps:

A.) Two- or four-chamber models only: Take the connector end of it into the control board. (Plug it in where you see two rows of header pins close together, five pins in each row.) If necessary, in the wiring diagram for your page 29).

NOTICE: If you have a two- or fourchamber model, you must orient the plug as shown in Figure 5, page

14. If you plug it in backwards, it will not cause damage, but the display will not work. If the display does not work a er you have completed installa on, 1.) disconnect power at all branch circuits, 2.) disconnect the plug, 3.) rotate it 180-degrees, then 4.) plug it back in.

WARNING! Be sure the cover is reinstalled and secured to reduce the risk of fire and electric shock.

C.) Restore power to the water heater. Verify proper operation.

Replacement Parts

The following parts may be ordered through your retailer or local plumbing wholesaler:

(temperature sensors)

When ordering replacement parts, please be ready to provide your water heater model and serial number.

WIRING DIAGRAMS

The wiring diagrams for various models are listed in this sec on. Locate the one that corresponds with your model.

NOTICE: The correct wiring diagram for your model can be found on the inside

The wiring diagrams are listed as follows:

(see below).

VAC (see below).

240/208 VAC, p. 30.

p. 30.

VAC (other than 16kW, 18kW, or

14kW/208V), p. 31.

VAC (16 kW, 18kW and

14kW/208V only), p. 32.

Level

Detect

Moisture

Sense

TH-AUX

TH-IN

TH-OUT

1 Chamber, 1 Element, 120 VAC

GRN

Control

Board

3-Pin Conn.

RED

Relay 1

BLK

Relay 2

VAC, p. 33.

page 8.

Element

Level

Detect

Moisture

Sense

TH-AUX

TH-IN

TH-OUT

1 Chamber, 1 Element, 240/208 VAC

GRN

Control

Board

3-Pin Conn.

RED

Relay 1

BLK

Relay 2

Element

Power

Supply

BLK

RED

GRN

GR

N

Ground

USE COPPER CONDUCTORS ONLY WHEN

CONNECTING TO ELECTRICAL SERVICE.

BLK

RED

GRN

L1

N

GRND

Power

Supply

BLK

RED

GRN

GR

N

Ground



BLK

RED

GRN

L1

L2

GRND

Level

Detect

Moisture

Sense

1 Chamber, 1 Dual Element, 240/208 VAC

GRN

3-Pin Conn.

Relay 1

RED

RED

Relay 2

BLK

TH-AUX Relay 1

RED

TH-IN

BLK

RED

BLK Element

TH-OUT

Relay 2

BLK

Control Board

RED

BLK Element

Level

Detect

Moisture

Sense

TH-AUX

TH-IN

1 Chamber, 1 Element, 277 VAC

GRN

Control

Board

3-Pin Conn.

RED

Relay 1

BLK

TH-OUT

Relay 2

Power

Supply

GRN

BLK

RED

GRN

Ground



BLK

RED

GRN

L1

L2

GND

Element

Power

Supply

GRN

GR

N

GR

N

Ground

BLK

RED

GRN

L1

L2

GRND

Transformer

Board




Moisture

Sense

Level

Detect

TH-1

TH-2

RED

BLK

Relay 2

BLK

BLK

Relay 3

BLK

RED

Relay 1

RED

RED

Relay 4

RED

TH-IN

Power

Supply

RED

BLK

RED

BLK

GRN

RED

BLK

L1

L2

Ground

Display



NOTICE: 16 kW and 18 kW two-chamber models DO NOT use this con  gura on.

14kW, 208V models DO NOT use this con  gura on.

For two circuit, two-chamber models, see page 32. Failure to observe this no ce can result in equipment malfunc on.


Used ONLY with the following two-chamber models:

Moisture

Sense

Level

Detect

TH-1

TH-2

RED

BLK

Relay 2

BLK

BLK

Relay 3

BLK

RED

Relay 1

RED

Relay 4

RED

Power

Supply

RED

TH-IN

BLK

RED

BLK

GRN

RED

BLK

RED

BLK

L1

L2

L1

L2

CIRCUIT

BREAKER

A

CIRCUIT

BREAKER

B

Ground

Display



NOTICE: This wiring diagram applies to the following two-chamber models only: 16 kW, 18 kW, and

14 kW/208 V. If you have a two-chamber model that is rated other than 16 kW, 18 kW, or

14 kW/208V, refer to page 31. Failure to observe this no ce can result in equipment malfunc on.


Moisture

Sense

Level

Detect

TH-1

TH-2

TH-3

TH-4

TH-IN

RED

BLK

GRN

Ground

BLK

BLK

BLK

Relay 2

BLK

BLK

Relay 4

BLK

RED

Relay 1

RED

RED

Relay 3

RED

Relay 6

BLK RED

Relay 5

RED

Power

Supply

Relay 8

RED

Relay 7

RED

J7

BLK

RED

BLK

RED

BLK

L1

L2

L1

L2

CIRCUIT

BREAKER

A

CIRCUIT

BREAKER

B

Display



APPENDIX: HORIZONTAL MOUNTING OF POU MODELS

As stated on page 12, point-ofuse (POU) models may be mounted horizontally. Note the following: horizontally, it must be mounted with brackets (provided). The nipples must face toward the right as shown in Figure 27.

models cannot be mounted horizontally. They must be mounted vertically (nipples facing upward).

Figure 27.

Horizontally-mounted POU water heater:

12.

NOTICE:

(Figure 2, page 11) before you start.

Figure 28.

Mount the brackets to the surface as shown.

See Figure 29 for fastener loca ons.

1

Complete the installa on steps on pages 11 and

12. Stop when you have completed step 7 on page 12.

2

Secure both brackets to the wall. (See Figure 28.) Use screws, bolts, or anchors as appropriate. NOTE: To drill pilot holes for the #10 screws that are provided,

Figure 29.

Pilot hole center distances:

Ensure that the mounting surface and fasteners will support the weight of the water heater.

Continued on the next page.

4.31 inches

(4 )

11.22 inches

(11 )

3

Set the water heater on the brackets, base plate down, and secure it with four sets of bolts and nuts. See Figure 30 and

Figure 31.

NOTICE: Ensure that the nipples face toward the right as shown in Figure

27, page 34.

4

Return to page 12 to complete the water heater installation.

Figure 30.

Internal water heater components are represented by hidden lines.

Water Heater

Components

Base Plate

Bolts (X4)

(Bolt heads face upward)

Figure 31.

Internal water heater components are represented by hidden lines.

Water Heater

Components

Brackets (X2)

Nuts (X4)

Surface

Surface

Copyright © 2018 A.O. Smith Corpora on. All rights reserved.

A.O. Smith R4MR-320E Signature 240-Volt 32-kW 2.8-GPM Tankless Electric Water Heater Use & care guide 36 Pages

A.O. Smith R4MR-320E Signature 240-Volt 32-kW 2.8-GPM Tankless Electric Water Heater Use & care guide

Installa on Instruc ons and Use & Care Guide

Electric Tankless

Water Heater

PLEASE DO NOT RETURN THIS UNIT TO THE

STORE.

Table of Contents ..............................Page

IMPORTANT SAFETY INFORMATION

Read and follow all safety messages and instruc ons in this manual.

Important informa on to keep...

DANGER

WARNING

CAUTION

NOTICE

General Requirements

RISKS DURING INSTALLATION

AND MAINTENANCE

RISKS DURING OPERATION

GENERAL INFORMATION

Introduction

Component

Descriptions

Temperature and Pressure

Relief Valve

Component Identification: Point-of-Use Models (RPV, CPV)

Component Identification: Two-Chamber Models (R2V, C2V)

Component Identification: Four-Chamber Models (R4L, C4L, R4M, C4M)

General Specifications

Models

Point-of-Use:

RPV, CPV

Two Chamber:

R2V, C2V

Four Chamber:

R4L, C4L, R4M, C4M

Wiring & Circuit Breaker

Requirements

Water Connections

Weight lbs. (kg)

Water Heater

Dimensions*

Electrical Requirements

Point-of-Use Models

Point-of-Use Models

Two-Chamber Models

*2**-140-X

*2**-120-E

*2**-140-E

*2**-160-E

*2**-180-E

Four-Chamber Models (Single Phase)

INSTALLATION

Getting Started

Clearances

Code Compliance

3

Connect the

Water Lines

5

Test Water

Heater Operation

Figure 5.

Ribbon Cable

Two- and four-chamber models only:

Red Band

on Board

Ribbon Cable

Connector

Control Board

NOTICE:

When plugging the display

(User Interface Module) into the control board, orient it as shown in this graphic.

OPERATION

Water Temperature

Adjustment

Point -of-use models only:

Two- or four-chamber models only:

Figure 6.

Figure 7 .