3.Using a Philips screwdriver, unscrew the bottom screw securing the outer door, see Figure 8.

4.Lift up and remove front panel.

FIGURE 8.

Thermostat REMOVAL / REPLACEMENT

REMOVAL

1.Turn off and unplug the water heater from the electrical outlet.

2.Remove the front panel, see the “REMOVING THE FRONT PANEL” section in this manual. Remove the insulation pad.

3.Using a 7mm wrench, loosen the nuts securing the high limit switch to the tank enough to rotate the switch 90° counterclockwise and slide it out from beneath the bracket. It is not necessary to remove the nuts completely.

4.Remove the 3 wires (white, brown, and green/yellow) from the thermostat at the spade connections, carefully taking note of the original location of each wire.

5.Unscrew the 2 screws securing the thermostat to the front panel and remove thermostat.

FIGURE 9.

REPLACEMENT

1.Place the new thermostat against the front panel and secure it with the two screws.

2.Reattach the wires at the spade connections, taking care to place them in their original locations. Be sure to push the connector completely onto the spade terminals.

3.Secure the temperature sensor to the tank by tightening the nuts. Be sure the sensor is firmly in contact with the tank surface.

4.Replace the insulation block and the front panel.

ELEMENT CLEANING / REPLACEMENT

To remove the element from the tank in order to clean or replace it:

1.Turn off and unplug the water heater from the electrical outlet and follow “DRAINING INSTRUCTIONS.”

2.Remove the front panel, see the “REMOVING THE FRONT PANEL” section in this manual. Remove the insulation pad.

3.Remove the two screws from the mounting bracket, see Figure 10, being careful not to drop the screws into the unit, as they will be difficult to retrieve. Remove bracket and set screws aside.

4.Remove the two spade connectors from the element.

5.Using a 10mm wrench, remove the four nuts around the element flange. Set nuts and lockwashers aside.

6.Lift element up to clear the four mounting bolts, rotate 15° clockwise, and lift out.

7.Discard the old gasket and clean the area around the element opening. Remove any sediment from or around the element opening and inside the tank.

8.If you are cleaning the element you have removed, do so by scraping or soaking in vinegar or a deliming solution.

NOTE: Replacement elements must (1) be the same voltage and (2) no greater wattage than listed on the model rating plate affixed to the water heater.

9.A new gasket must be used in all cases to prevent a possible water leak. Place new element gasket in the element opening over the four element bolts, orienting the gasket bulge facing water side.

10.Insert the curved part of the element, rotate 20° clockwise, and continue to insert the element, being sure that the four bolts fit into the element flange.

11.Replace the four lockwashers and 10mm nuts. Tighten until snug.

DO NOT OVERTIGHTEN.

12.Place unit back on wall mounting bracket hooks. Reconnect the

15

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A.O. Smith AOSRE50400 warranty Thermostat Removal / Replacement, Element Cleaning / Replacement, Do not Overtighten
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AOSRE50400 specifications

A.O. Smith AOSRE50400 is a high-efficiency water heater that exemplifies advanced technology and engineering, making it a popular choice for residential and commercial applications. This model is part of A.O. Smith’s comprehensive line of water heating solutions and is designed to provide reliable performance while maximizing energy efficiency.

One of the standout features of the AOSRE50400 is its high energy factor (EF), which greatly contributes to reduced energy bills and a smaller environmental footprint. With an EF rating of approximately 0.95, this water heater utilizes innovative design techniques to ensure that more of the energy consumed is converted into usable hot water. It meets and often exceeds the stringent energy efficiency standards set by the Department of Energy.

The AOSRE50400 is equipped with advanced insulating materials, which minimize heat loss and improve overall efficiency. This is particularly beneficial in maintaining water temperature for extended periods, reducing the need for excessive reheating. The tank has been designed with a glass-lined interior that offers enhanced durability and resistance to corrosion, extending the lifespan of the unit.

Another important characteristic of the AOSRE50400 is its large capacity. With a tank size of 50 gallons, it can effectively meet the hot water demands of medium to large households or businesses. This capacity allows for simultaneous usage across multiple outlets, ensuring that you never run out of hot water when you need it most.

The digital display and user-friendly interface provide homeowners with easy control over temperature settings and operation modes. This feature enhances user convenience and allows for customized hot water delivery that can cater to specific usage needs. Furthermore, the built-in diagnostic system alerts users to any potential issues, ensuring timely maintenance and reducing the risk of costly repairs.

A.O. Smith also prioritizes safety in the design of the AOSRE50400. It comes with multiple safety features, including a temperature and pressure relief valve, which helps prevent potential overpressure situations. This commitment to safety ensures peace of mind for users and compliance with local plumbing codes.

In summary, the A.O. Smith AOSRE50400 water heater exemplifies modern engineering and technology, offering high energy efficiency, a durable design, user-friendly controls, and a strong commitment to safety. Its large capacity and advanced features make it an exceptional choice for those seeking reliable and efficient hot water solutions.
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