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 build-up should be measured periodically. Heaters will have about 3” of lime build-up when the level of lime has reached the bottom of the cleanout opening or about 1” of lime build-up 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” build-up of lime.

Example 1 = Initial inspection, after 1 year, shows 1/2” of lime accumulation. Therefore, the heater can be delimed once a year.

Example 2 = Initial inspection, after 1 year, shows 2” of lime accumulation. Therefore, the heater should be delimed every 3 months.

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

Heater failure due to excessive lime build-up voids the warranty.

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

To dissolve and remove the more stubborn mineral deposits, A.O. Smith UN•LIME Professional Delimer should be used.

A. O. Smith UN-LIME 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 (part no. 4763) and 5 gallon (part no. 4813) sizes. Hydrochloric acids are not recommended for use on glass-lined tanks.

A. O. Smith Form no. 4800, 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.

To clean heater through cleanout opening, proceed as follows:

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

2.Remove outer cover plate from lower side of heater jacket.

3.Remove plug from cleanout opening.

•Place a short pipe nipple into the tank to extend beyond the heater jacket.

4.Remove lime, scale and sediment using care not to damage the glass coatings inside the tank.

5.Remove the nipple.

6.Replace cleanout plug.

7.Follow filling instructions when restoring hot water service..

8.Check for water leakage and correct as necessary.

9.Replace outer jacket cover plate.

RELIEF VALVE

At least twice a year, the temperature and pressure relief valve should be checked to ensure that it is in operating condition. To check the relief valve, lift the lever at the end of the valve several times. The valve should seat properly and operate freely.

CAUTION

BEFORE MANUALLY OPERATING THE VALVE, MAKE SURE THAT A DRAIN LINE HAS BEEN ATTACHED TO THE VALVE TO DIRECT THE DISCHARGE TO AN OPEN DRAIN. FAILURE TO TAKE THIS PRECAUTION COULD MEAN CONTACT WITH EXTREMELY HOT WATER PASSING OUT OF THE VALVE DURING THIS CHECKING OPERATION.

If the temperature and pressure relief valve on the heater discharges periodically or continuously, it may be due to the thermal expansion of water in a closed water supply system, or it may be due to a faulty relief valve.

Thermal expansion is the normal response of water when it is heated. In a closed system, thermal expansion will cause the system pressure to increase until the relief valve actuation pressure is equaled. Then, the relief valve will open, allowing some water to escape slightly lowering the pressure. (See THERMAL EXPANSION Section of pages 5 and 6).

Contact your water supplier or local plumbing inspector on how to control this situation.

ABOVE ALL, DO NOT PLUG THE TEMPERATURE AND PRESSURE RELIEF VALVE. THIS IS NOT A SOLUTION AND CAN CREATE A HAZARDOUS SITUATION.

POWER BURNER

KEEP THE AREA AROUND THE BURNER CLEAR AND FREE OF COMBUSTIBLE MATERIALS, GASOLINE OR OTHER FLAMMABLE LIQUIDS OR VAPORS. DO NOT OBSTRUCT

13

Page 12 Page 14
Page 13
Image 13
A.O. Smith COF, COBT, BTPN, BTP-140-140 thru 600-2500 warranty Relief Valve, Power Burner
Page 12 Page 14

BTP-140-140, BTPN, BTP-140-140 thru 600-2500, COF, COBT specifications

A.O. Smith, a renowned leader in water heating technology, offers a range of high-efficiency commercial boilers, including the COBT, BTP-140-140 through BTP-600-2500, BTPN, and COF models. Designed to cater to diverse heating needs, these systems are engineered for optimal performance, reliability, and efficiency, making them ideal for various applications, from hospitality to industrial processes.

The A.O. Smith COBT model stands out for its innovative features, such as a fully modulating burner that adjusts output based on demand, enhancing energy efficiency and ensuring consistent comfort. Its compact design allows for easy installation in limited spaces, while robust construction materials ensure longevity. The integrated controls offer real-time monitoring and diagnostics, allowing operators to maintain peak performance and reduce maintenance costs.

The BTP series, particularly the BTP-140-140 through BTP-600-2500, delivers high heating capabilities with a range of output options. These models feature a sophisticated heat exchanger design that maximizes heat transfer efficiency while minimizing energy consumption. The use of dual-fuel capability provides flexibility, allowing users to switch between natural gas and propane, thus enhancing operational resilience. The BTP units are also equipped with advanced modulating burners that adapt to varying load conditions, further optimizing fuel usage.

For applications requiring enhanced performance, the BTPN models offer additional features like integrated pumps and a larger footprint for increased capacity. This makes them ideally suited for high-demand environments where consistent hot water supply is critical. The COF model complements this lineup, focusing on oil-fired applications and delivering reliability across diverse operating conditions.

In terms of technology, A.O. Smith utilizes cutting-edge combustion systems and advanced control technologies that not only enhance efficiency but also meet stringent emission standards. The incorporation of condensing technology in many models enables users to harness latent heat from flue gases, significantly improving overall system efficiency.

Overall, A.O. Smith's COBT, BTP, BTPN, and COF models are engineered with a commitment to quality, efficiency, and user-friendliness. Their reliability, advanced technologies, and versatile applications make them a preferred choice for businesses looking for durable and efficient heating solutions. Whether for commercial or industrial needs, A.O. Smith continues to set the standard for water heating systems.
Top Page Image Contents