Maintenance Schedule, Flushing | A.O. Smith BTH 300A, BTH 400A

MAINTENANCE SCHEDULE

Following are the instructions for performing some of the recommended maintenance. Unit inspection and adjustment should be performed by a competent technician.

COMPONENT	OPERATION	INTERVAL	REQUIRED

Tank	Sediment	Monthly	Flushing
	Removal

Tank	Lime Scale	Semi	UN-LIME®
	Removal	Annually	Delimer

Powered Anode	Inspect	Semi
System		Annually

Relief Valve	Inspect	Semi
		Annually

	Clean Inlet
Blower	Screen and	As Required	Soft Brush
	Blower Wheel

Vent System	Inspect	Every 3	Joints should
		Months	be sealed

(1) If furnished with oiling provision.

NOTE: UN•LIME is not available in Canada. Please call Customer Service at 1-800-265-8520 for approved alternatives.

FLUSHING

1.Turn off the heater electrical disconnect switch.

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

3.Close the drain valve when finished flushing.

4.Turn on the heater electrical disconnect switch.

DRAINING

The heater must be drained if it is to be shut down and exposed to freezing temperatures. Maintenance and service procedures may also require draining the heater.

1.Turn off the heater electrical disconnect switch.

2.Close the cold water inlet valve to heater.

3.Open a nearby hot water faucet to vent the system.

4.Open the heater drain valve.

5.If the heater is being drained for an extended shutdown, it is suggested the drain valve be left open during this period.

• Follow FILLING instructions when restoring hot water service.

SEDIMENT REMOVAL

Waterborne impurities consist of the particles of soil and sand which settle out and form a layer of sediment on the bottom of the tank.

For convenience, sediment removal and lime scale removal should be performed at the same time.

LIME SCALE REMOVAL

The amount of calcium carbonate (lime) released from water is in

direct proportion to water temperature and usage. The higher the water temperature or water usage, the more lime deposits are dropped out of the water. This is the lime scale which forms in pipes, heaters and on cooking utensils.

Lime accumulation not only reduces the life of the equipment but also reduces efficiency of the heater and increases fuel consumption.

The usage of water softening equipment greatly reduces the hardness of the water. However, this equipment does not always remove all of the hardness (lime). For this reason it is recommended that a regular schedule for deliming be maintained.

The depth of lime buildup should be measured periodically. Heaters will have about 3" (7.6cm) of lime buildup when the level of lime has reached the bottom of the cleanout opening or about 1" (2.5cm) of lime buildup if it has reached the drain valve opening. A schedule for deliming should be set up, based on the amount of time it would take for a 1" (2.5cm) buildup of lime.

Example 1:

Initial inspection shows 1/2" (1.3cm) of lime accumulation. Therefore, the heater can be delimed once a year.

Example 2 :

Initial inspection shows 2" (5cm) of lime accumulation. Therefore, the heater should be delimed every 3 months.

Sediment and lime scale removal may be accomplished through the cleanout opening furnished on the heater, see Figure 24. The heater must be drained, see DRAINING, before removing cleanout cover on tank.

FIGURE 24.

To dissolve and remove the more stubborn mineral deposits, A.O. Smith UN•LIME® Professional Delimer should be used. NOTE: UN•LIME is not available in Canada. Please call Customer Service at 1-800-265-8520 for approved alternatives.

A.O. Smith UN•LIME® Professional Delimer is an easy to handle patented food grade acid formulated specifically for lime scale removal from all types of water using equipment. Available in 1 gallon (3.8L) (part no. 4763) and 5 gallon (19L) (part no. 4813) sizes. Hydrochloric base acids are not recommended for use on glass-lined tanks.

A.O. Smith Form No. 4800 Rev. 8, entitled “Why, When and How”, describes tank cleaning methods and materials. UN•LIME and the booklet may be obtained through your A.O. Smith dealer or distributor.

The cleanout opening is shown in Figure 24. To clean heater through cleanout opening, proceed as follow:

1.Turn off water inlet valve, the heater electrical disconnect switch and open drain valve.

BTH 300A, BTH 400A specifications

A.O. Smith has established itself as a leader in the water heating industry, offering a range of products that combine efficiency, reliability, and innovative technology. Among these products, the BTH 300A and BTH 400A models stand out for their advanced features and robust performance, catering to both residential and commercial needs.

The BTH 300A and BTH 400A are high-efficiency water heaters designed with cutting-edge condensing technology, allowing for significant energy savings compared to traditional water heating systems. These models utilize a modulating gas valve that adjusts the burner operation based on the demand for hot water. This smart system not only enhances efficiency but also ensures a consistent supply of hot water without the worry of fluctuations.

One of the standout features of the BTH series is its compact design. Both the BTH 300A and BTH 400A are engineered to fit into smaller spaces, making them ideal for properties with limited installation areas. Their lightweight construction and user-friendly installation features further simplify the process, ensuring that homeowners and professionals alike can set them up with ease.

The BTH models are equipped with advanced control systems that offer precise temperature adjustment capabilities. Users can easily customize their hot water settings to meet specific household or business requirements. This adaptability is supported by the built-in digital display, which provides real-time information about the operating status of the unit.

Safety is a key consideration in the design of the BTH 300A and BTH 400A. They feature a robust set of safety mechanisms, including temperature lockout and venting safeguards, ensuring reliable operation and peace of mind for users. A.O. Smith also understands the importance of longevity in water heaters, and these models are built with high-quality materials, making them resistant to corrosion and wear over time.

In terms of performance, both the BTH 300A and BTH 400A models deliver exceptional heating capabilities, capable of meeting high demands while maintaining efficiency. With customer satisfaction at the forefront, A.O. Smith backs these units with an extensive warranty, demonstrating their commitment to quality and long-term performance.

In summary, the A.O. Smith BTH 300A and BTH 400A water heaters exemplify the marriage of innovation and functionality. With their energy-efficient operation, customizable settings, compact design, and advanced safety features, these models are a compelling choice for those in need of reliable and effective hot water solutions.