Checklist, System Water Test | A.O. Smith NW 37-670 instruction

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

•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 tank cleanout.

•The make-up water valve and boiler drain valve may be opened to flush during the cleanout process.

8.Clean remaining gasket material from tank and element flanges. Do not reuse original element gasket. The element gasket is Part No. 5109.

9.Replace elements as follows:

•Put a new gasket on each element.

•Install into tank opening.

•Uniformly tighten element bolts. Torque to approximately 32 ft/lbs.

10.Connect element wiring as necessary.

11.Follow FILLING instructions to restore boiler to service.

•Check for water leaks around elements and proper operation when boiler is filled.

•Replace insulation and cabinet panel.

CHECKLIST

Before calling for service, check the following points to see if the cause of trouble can be identified and corrected. Reviewing this checklist may eliminate the need of a service call and quickly restore the boiler to service. The illustration on page 5 identifies the location of most of the boiler components.

BE SURE TO TURN OFF THE ELECTRICITY WHEN CHECKING EQUIPMENT.

Not enough or no heat

1.Be certain the electrical disconnect switch serving the boiler is in the ON position. The pilot switch(es) on the cabinet front should be on.

•In some installations the boiler electrical service may be limited by the power company or boiler controls. If the boiler operates on a controlled circuit heat may be effected.

2.Check the fuses.

•The electrical disconnect switch usually contains fuses.

•The boiler has fuses located behind the cabinet door, see page 5 for location.

3.If the water was excessively hot, and is now cold, the high temperature cutoff may have operated (manual reset equipped models).

•To reset, turn off electricity and remove the back panel and push the reset button.

•Repeated operation of the high temperature cutoff should be investigated by your servicer.

4.The capacity of the boiler may have been exceeded by a large demand for heat.

•Large demands require a recovery period to restore water temperature.

5.Sediment or lime scale may be affecting boiler operation. Refer to MAINTENANCE for details.

Water is too hot

1. Refer to TEMPERATURE REGULATION.

Boiler makes sounds

1.Sediment or lime scale accumulation on the elements may cause sizzling and hissing noises when the boiler is operating.

•The sounds are normal , however, the tank bottom and elements should be cleaned. Refer to MAINTENANCE for details.

2.Some of the electrical components of the boiler make sounds which are normal.

•Contactors will “click” or snap as the boiler starts and stops.

•Transformers and contactors often hum.

Water leakage is suspected

1.Check to see if the drain valve is tightly closed.

2.If the outlet of the relief valve is leaking it may represent:

•Excessive water pressure or air in the system.

•Faulty relief valve.

3.Examine the flange area of the elements and tank cleanout for gasket leakage.

•Tighten the bolts or, if necessary, follow the WATER AND LIME SCALE REMOVAL procedure to replace the gaskets.

SYSTEM WATER TEST

System water test

Review SYSTEM CLEANING section, for a description of six problems which result from loss of system chemical stability. Chemical stability is checked by:

1.Draw off water from system. Is it dirty, discolored or odorous?

2.What is the pH of the system water? It should be neutral or slightly alkaline.

3.Does “air” purged from system vents burn? If so, the “air” is actually gas.

If any of the above conditions are present, all waterways should be cleaned and the water adjusted to an alkaline condition.

If you cannot identify or correct the source of malfunction:

1.Place the boiler electrical disconnect switch in the OFF position.

2.Close the make-up water inlet valve to the boiler.

3.Contact your servicer.

NW 37-670 specifications

A.O. Smith NW 37-670 is a highly regarded water heater that stands out in the residential water heating market. Renowned for its efficiency and reliability, this unit offers homeowners a perfect blend of advanced technology, high performance, and convenience.

One of the main features of the A.O. Smith NW 37-670 is its high recovery rate, which allows for rapid heating of water to meet the demands of a busy household. With a 37-gallon tank capacity, this model can effectively supply hot water for various applications, such as showers, dishwashing, and laundry. The design incorporates a powerful heating element that ensures the water is heated quickly, thus minimizing wait times and improving overall comfort.

Efficiency is a cornerstone of the NW 37-670's design. This water heater features an impressive Energy Factor (EF), which translates to lower energy bills for homeowners. A.O. Smith has integrated advanced insulation materials to maintain water temperature longer, reducing the energy required for reheating. This not only helps in cutting down costs but also promotes eco-friendliness, making it an excellent option for environmentally conscious consumers.

The technology behind the A.O. Smith NW 37-670 includes a state-of-the-art electronic control system. This system continuously monitors the unit's performance and adjusts operations to optimize efficiency. Additionally, the water heater is equipped with a robust diagnostic system that provides real-time feedback, making it easier for homeowners to identify any potential issues before they escalate.

Durability is another defining characteristic of the NW 37-670. Constructed with high-quality materials, including a glass-lined tank for added protection against corrosion, this water heater is designed to last for years with minimal maintenance. The anode rod further enhances its longevity by reducing the potential for rust and increases the lifespan of the unit.

Installation and maintenance are straightforward due to the user-friendly design of the A.O. Smith NW 37-670. It can fit into various spaces, making it a versatile option for both new constructions and replacement projects. A.O. Smith also provides comprehensive support and warranty services, ensuring customer satisfaction and peace of mind.

In summary, the A.O. Smith NW 37-670 is a top-tier water heater that combines efficiency, advanced technology, and durable construction. With its substantial capacity, rapid recovery rate, and modern control features, it is an excellent choice for any home looking for dependable hot water solutions.