Flushing, Sediment Removal | A.O. Smith DVE-150, DHE-200 instruction

Temperature-Pressure Relief Valve Operation

The temperature-pressure relief valve must be manually operated at least once a month. Lift the lever at the top of valve several times until the valve seats properly and operates freely, see Figure 2B.

When checking the temperature-pressure relief valve operation, make sure that (1) no one is in front of or around the outlet of the temperature- pressure relief valve discharge line, and (2) that the water discharge will not cause any property damage, as the water may be extremely hot. Use care when operating valve as the valve may be hot.

FIGURE 2B.

If after manually operating the valve, it fails to completely reset and continues to release water, immediately close the cold water inlet to the water heater, follow the draining instructions in the Operation section of this manual, and replace the temperature-pressure relief valve with a properly rated/sized new one, see Page 9.

If the temperature-pressure relief valve on the appliance weeps or dischargesperiodically,thismaybeduetothermalexpansion.Consultyour local water supplier or a Qualified ServiceAgency for further information. Do not plug the temperature-pressure relief valve.

Component	Operation	Interval	Required
	Flushing	Monthly
Tank	Sediment	As Needed
	Removal
	Lime Scale	As Needed	UN-LIME delimer
Elements	Removal		and element
			gaskets

table 6. maintenance schedule.

FLUSHING

1.Turn off the electrical disconnect switch.

2.Open the drain valve. Allow water to flow until it runs clean.

3.Close the drain valve when finished flushing.

4.Turn on the electrical disconnect switch.

SEDIMENT REMOVAL

Water borne impurities consist of fine particles of soil and sand which settle out and form a layer of sediment on the bottom of the tank. In time, if not removed, the level of sediment might reach the heating elements causing premature heating element failure.

For convenience, sediment removal and element lime scale removal should be performed at the same time as follows:

WATER AND LIME SCALE REMOVAL

Water and lime scale accumulations on the heating elements is a normal condition, common to all immersion type elements. Factors which affect the amount of this formation are:

1.Amount of hot water used. As the volume of water heated increases, more scale results.

2.Water temperature. As the temperature of the water is increased, more scale is deposited on the elements.

3.Mineral level characteristics of the water supply. Regardless of water treatment, the elements should be examined regularly.

STRANGE SOUNDS

Water scale accumulations may cause noises to occur during operation.

It is recommended that a lower heating element be removed periodically for examination. If it is scaled, all of the elements should be removed and cleaned. If the tank bottom has an accumulation of sediment, it should be cleaned.

Lime scale should be removed by dissolving the accumulation in UN-LINE delimer. UN-LIME is a non-muriatic delimer, available through water heater distributors. Do not use muriatic or hydrochloric acid base deliming solutions to remove lime scale from the elements.

All models: do not pour delimer into tank.

1.Turn off electrical disconnect switch.

2.Drain heater following DRAINING instructions, see Page 14.

3.Disconnect the wires attached to the elements terminals. Try not to disturb the wiring unnecessarily and reconnection will be easier.

4.Remove the bolts from each element and remove the elements from the openings.

Use a twisting, pulling action to remove elements scaled beyond the size of the tank openings.

Brush loose scale from elements.

Silicates, sulfates and aluminates must be removed by scraping or other mechanical means. Lime scale dissolvents will not remove these types of scale which are occasionally encountered.

5.Lime scale removal:

Place limed ends of heating elements into UN-LIME delimer and allow scale to dissolve. Do not permit delimer or water to contact heating element electrical terminals.

6.Flush cleaned ends of elements with water when deliming or cleaning is completed.

7.Remove sediment and scale from the tank bottom through the access provided by the element opening or tank cleanout, if furnished.

The cold water inlet valve and drain valve may be opened to air the cleanout process.

8.Clean remaining gasket material from tank and element flanges.

Do not reuse original element gasket.

9.Replace elements as follows:

Put a new gasket on each element.

Install into tank opening from which element was removed. Uniformly tighten element bolts. Torque to approximately 32 ft/lbs.

10.Attach wires to element terminals from which they were

removed.

11.Follow FILLING instructions in the Operation section of this manual to restore hot water service, see Page 14.

Check for water leaks around elements and proper operation when heater is filled and during operation.

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.