INSTALLATION. A.O. Smith RPVR-80E, *2**-120-E5 series, *P**-80-E5 series, R2VR-180E, R4MR-320E, *P**-55-E5 series, *4**-280-E5 series, RPVR-30K, *4**-280-X5 series, *4**-320-E5 series

INSTALLATION

Getting Started

electrical wires that will enter the heater from the side.

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.

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.

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

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

Install one

ƐƚĂŶĚŽīďƵŵƉĞƌĂƚ each corner.

;ϰƚŽƚĂů͖ƉƌŽǀŝĚĞĚ͘Ϳ

Figure 2.

Wall

Side View

8”

(20.3 cm)

12”

(30.5 cm)

Single

Chamber

Water Heater

Front

View

8”

(20.3 cm)

ENTER

°F

°C

8”

(20.3 cm)

Minimum Clearances

15”+

( 38.1 cm +)

8”

(20.3 cm)

Front Clearance:

15” + (38.1 cm +)

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

Maintain 12” (30.5 cm) MIN. clearance at

8”+

(20.3 cm +) inlet/outlet.)

Minimum Clearances

Wall or adjacent object

Code Compliance

• 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.

• Follow all other applicable plumbing, heating, and air conditioning codes during installation.

• Your water heater is designed to be installed indoors only.

• Locate your water heater in a 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.

• Your water heater and water lines must be protected from freezing.

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

• Avoid locations that are prone 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).

• Locate your water heater where it 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.

• Be sure that your water heater is accessible and that minimum

Electric Tankless Water Heater • 11

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

“Clearances” on page 11.

• Do not install your water heater underneath condensate lines.

• A drain pan, or other means of 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.

2 Mount Your

Water Heater

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 ff bumper to each corner on the back of the water heater. Stando ff s are provided. These stando ff 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 clearances. (See “Clearances” on 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 the water heater’s protective cover later.)

Figure 3.

ĐĐĞƉƚĂďůĞŽƌŝĞŶƚĂƟŽŶƐĨŽƌ ŵŽƵŶƟŶŐĂƉŽŝŶƚͲŽĨͲƵƐĞ;WKhͿ water heater: sĞƌƟĐĂů

Horizontal

EKd/͗ ͻhƐĞŵŽƵŶƟŶŐďƌĂĐŬĞƚƐ;ƉƌŽǀŝĚĞĚͿ

ĨŽƌŚŽƌŝnjŽŶƚĂůŵŽƵŶƟŶŐ͘EŝƉƉůĞƐ ŵƵƐƚƉŽŝŶƚƚŽǁĂƌĚƚŚĞƌŝŐŚƚ͘ ͻdǁŽͲĐŚĂŵďĞƌĂŶĚĨŽƵƌͲĐŚĂŵďĞƌ ŵŽĚĞůƐŵƵƐƚďĞŽƌŝĞŶƚĞĚǁŝƚŚƚŚĞ

ŶŝƉƉůĞƐĨĂĐŝŶŐƵƉǁĂƌĚ;ǀĞƌƟĐĂůͿ͘

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.

• Thread sealing tape (plumber’s 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.

• Use two wrenches when attaching the hot and cold water lines to

12 • Electric Tankless Water Heater

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

• Flexible water supply hoses are recommended for your installation.

• Well water must be treated.

• Only potable water can be used with this water heater. Do not introduce pool or spa water, or any chemically treated water into the water heater.

• Do not connect to a saltregenerated water softener or a water supply of salt water.

• The warranty will not cover damage caused by water quality.

pressure: 50 to 60 psi. Higher pressures require a pressure reducing valve.

• Installations above the ceiling or in an attic require a bleed air separator.

• A properly-sized arrestor should be installed where water hammer exists.

NOTICE: Do not supply electrical power to your water heater yet. If you

Figure 4 .

Hot Cold 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.

4 Install Electrical

Service

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 remove the circuit’s fuses).

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

3. Check the water heater’s ra ng plate and ensure that the electrical service’s voltage, wiring size

Electric Tankless Water Heater • 13

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

NOTICE: The electrical requirements for your model are listed in “Electrical Requirements” which starts on page 8.

4. Connect the electrical service as described in “Electrical

Requirements” (starting on page

8).

There is a wiring diagram label on the inside of your water heater’s protective cover. See also “Wiring

Diagrams” on page 29 of this 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 correct. (Refer to “Electrical

Requirements” which starts 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 of the cover’s ribbon cable into 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, refer to the “DISPLAY” callout in the wiring diagram for your model. (See “Wiring Diagrams” on 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.

8. Reinstall the water heater’s cover.

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

9. Turn on power to the water heater.

10. Verify proper operation.

Figure 5.

Ribbon Cable

Operating instructions are listed on page 15.

5

Test Water

Heater Operation

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

□ You should hear a “click” as the heater’s relays engage.

□ 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 system’s feedback will help you iden fy the issue. See “Troubleshoo ng” for more informa on (page 17 or 19).

Two- and four-chamber models only:

Red Band

“TX” Label

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.

14 • Electric Tankless Water Heater