Maintenance, Temperature Adjustment | A.O. Smith DVE-150, DHE-200

instructions for installation of the valves. Before changing the factory setting on the thermostat, read the entire “Temperature Regulation” section in this manual.

It is recommended that lower water temperatures be used to avoid the risk of scalding. It is further recommended, in all cases, that the water temperature thermostat be set for the lowest temperature which satisfies your hot water needs. This will also minimize water scale formations on the heating elements and provide the most energy efficient operation of the water heater. Thermostat(s) are factory set at 120°F (49°C) unless specified differently by state requirements.

KEEPING THE THERMOSTAT SETTING AT 120°F WILL REDUCE THE RISK OF SCALDS.

Figure 1 shows the approximate time-to-burn relationship for

normal adult skin.

TEMPERATURE ADJUSTMENT

Always close and lock the cabinet door after making a temperature adjustment. Turn on electricity.

Thermostat Temperature Control

When the water heater circulating pump (optional) is provided, horizontal and vertical model heater thermostats may be set to 185°F if dishwasher rinse water is supplied by the heater.

Without the circulating pump, horizontal model heaters should be set not higher than 165°F. Vertical models may be set as desired, not to exceed 185°F.

Where multiple thermostats are used on a vertical model heater, they may all be set at the same temperature or 2° to 4°F apart to achieve “step control”. The bottom thermostat is set the hottest and the top thermostat the coolest.

Temperature		Time to Produce 2nd & 3rd
Settings		Degree Burns on Adult Skin

180°F (82°C)		Nearly Instantaneous
160°F (71°C)		About 1/2 second
150°F (66°C)		About 1-1/2 seconds
140°F (60°C)		Less than 5 seconds
130°F (54°C)		About 30 seconds
120°F (49°C)		More than 5 minutes
80°F (27°C)		- - - - - - - - - - - - - - - -
	FIGURE 1.

TEMPERATURE CONTROL (MECHANICAL THERMOSTAT)

FIGURE 2A.

Solid State Step Control (with or without modulation)

Additional instructional literature is provided with the heater sequencer control.

HIGH TEMPERATURE DEVICES

A manual reset temperature high limit is in the control circuit in addition to the automatic device previously described. The contacts open at 210°F and must be manually reset after the temperature hi-limit switch has been activated and the water temperature is below 210°F.

The reset button is located on the temperature hi-limit in the control cabinet of the heater. Disconnect the power before opening the door to push the reset button.

MAINTENANCE

General

Water heater maintenance includes inspection and testing of the Temperature Pressure Relief Valve, periodic tank flushing and cleaning, and removal of lime scale from the heating elements. Where used, water heating system circulating pumps should

be oiled.

Tank flushing and circulating pump lubrication should be performed in accordance with the maintenance schedule, see Table 6 on page 16. Tank sediment removal and element lime scale removal must be performed when needed as determined by periodic inspections.

ANODE INSPECTION AND REPLACEMENT

This water heater is equipped with a sacrificial anode. Anodes protect the glass-lined tank from corrosion by sacrificing themselves through electrolysis. When the anode material is consumed, there is no more protection and corrosion of the tank accelerates.

Inspection of the anode every 6 to 12 months allows you to identify a spent anode and replace it. Replace the anode when its diameter is 3/8” (1 cm) of an inch, or annually which ever is first. Aggressive, very hot and softened water causes rapid consumption of the anode requiring frequent inspections. Anodes are available from your distributor or A.O. Smith.

DVE-150, DHE-200 specifications

A.O. Smith has established itself as a leading brand in the water heating industry, and its DVE-150 and DHE-200 models showcase the company's commitment to efficiency and innovation. Both units are designed to cater to residential and commercial water heating needs, offering a range of features that enhance performance and reliability.

The DVE-150 is a high-efficiency electric water heater that boasts a 150-gallon capacity. It is ideal for larger households or small commercial applications where hot water demand is significant. One of the standout features of the DVE-150 is its advanced heating element technology. This model uses high-density insulation that reduces heat loss, ensuring more effective energy use. The unit operates at a high recovery rate, allowing it to provide consistent hot water quickly, even during peak usage times.

On the other hand, the DHE-200 is a gas water heater, equipped with a 200-gallon capacity. This model is ideal for high-demand environments where large volumes of hot water are required. The DHE-200 incorporates an innovative direct vent system that enhances efficiency and safety by removing combustion gases from the living space. The modulating gas burner further ensures that the unit operates at optimal efficiency, adjusting the heat output based on the demand for hot water.

Both models feature an intuitive digital display that allows users to monitor and adjust their settings easily. Additionally, they come with advanced diagnostic tools that provide real-time feedback on the system's performance, making maintenance easier and more efficient.

Safety is a top concern for A.O. Smith, and both the DVE-150 and DHE-200 are designed with multiple safety features. These include high-temperature limit switches, pressure relief valves, and flame rollout switches, all of which work to protect the unit from potential hazards.

In terms of installation, both models offer flexible options. They are designed to fit in various spaces, accommodating different installation environments. This versatility is essential for both new constructions and retrofitting older systems.

The DVE-150 and DHE-200 are also backed by A.O. Smith's industry-leading warranty, providing customers with peace of mind regarding their investment. Overall, these models embody A.O. Smith's dedication to quality, efficiency, and safety, making them excellent choices for those in need of reliable water heating solutions.