SECTION IV: TANKLESS & Indirect Water HEATER PIPING

A. CONNECT TANKLESS HEATER PIPING as shown in Figure 12. See Table 4 for Tankless Heater Rating.

WARNING

Install automatic mixing valve at tankless heater outlet to avoid risk of burns or scalding due to excessively hot water at fixtures. Adjust and maintain the mixing valve in accordance with the manufacturer's instructions. Do not operate tankless heater without mixing valve.

THE FOLLOWING GUIDELINES SHOULD BE FOLLOWED WHEN PIPING THE TANKLESS HEATER:

1.FLOW REGULATION — If flow through the heater is greater than its rating, the supply of adequate hot water may not be able to keep up with the demand. For this reason a flow regulator matching the heater rating should be installed in the cold water line to the heater. The flow regulator should preferably be located below the inlet to the heater and a minimum of 3’ away from the inlet so that the regulator is not subjected to excess temperatures that may occur during “off” periods when it is possible for heat to be conducted back through the supply line. The flow regulator also limits the flow of supply water regardless of inlet pressure variations in the range of 20 to 125 psi.

2.TEMPERING OF HOT WATER — Installation of an automatic mixing valve will lengthen the delivery of the available hot water by mixing some cold water with the hot. This prevents the possibility of scalding hot water at the fixtures. In addition, savings of hot water will be achieved since the user will not waste as much hot water while seeking a water temperature. Higher temperature hot water required by dishwashers and automatic washers is

possible by piping the hot water from the heater prior to entering the mixing valve. The mixing valve should be “trapped” by installing it below the cold water inlet to heater to prevent lime formation in the valve. Refer to Figure 12.

3.FLUSHING OF HEATER — All water contains some sediment which settles on the inside of the coil. Consequently, the heater should be periodically back washed. This is accomplished by installing hose bibs as illustrated and allowing water at city pressure to run into hose bib A, through the heater, and out hose bib B until the discharge is clear. The tees in which the hose bibs are located should be the same size as heater connections to minimize pressure drop.

4.HARD WATER — A water analysis is necessary to determine the hardness of your potable

water. This is applicable to some city water and particularly to well water. An appropriate water softener should be installed based on the analysis and dealer’s recommendation. This is not only beneficial to the tankless heater but to piping and fixtures plus the many other benefits derived from soft water.

NOTICE

During summertime operation, the normal water line on a steam boiler can be raised 1", from 28-7/8" to 29-7/8" (see Figure 1) for improved tankless heater performance on steam boilers.

Use street elbow fittings in tankless in and out connections to assure adequate clearance of piping.

CAUTION

Use of hard water with a tankless coil will, over a short period of time, reduce the output of the coil and reduce the useful life of the coil.

24

Page 23 Page 25
Page 24
Image 24
Burnham MST288, MST396, MST629, MST513 manual Section IV Tankless & Indirect Water Heater Piping
Page 23 Page 25

MST513, MST396, MST629, MST288 specifications

The Burnham MST series, comprising models MST396, MST629, MST513, and MST288, is renowned for its robust design and exceptional performance in the boiler industry. Each model is engineered to provide optimal efficiency and reliability for residential and commercial heating applications.

The Burnham MST396 is distinguished by its high thermal efficiency and advanced combustion technology. This model features a cast iron heat exchanger which ensures superior heat retention and distribution. The MST396 is equipped with a powerful burner that allows for variable firing rates, maximizing efficiency and extending the lifespan of the unit. Additionally, it includes a built-in electronic ignition system that enhances reliability while reducing the need for frequent maintenance.

Moving to the MST629, this model is designed for larger applications needing higher output. It boasts a significant BTU input and utilizes a multi-stage burner system. This ensures optimal combustion and adapts to varying demand, providing consistent heat without wasting energy. The MST629 also incorporates enhanced insulation and an advanced flue gas venting system to improve safety and minimize energy loss.

The MST513 caters to mid-sized applications with its adaptable performance and user-friendly features. This model is notable for its compact design, making it suitable for installations with limited space. It uses a two-stage burner for efficient energy use and offers a smart control system that monitors performance in real-time. This allows users to make informed decisions about their energy consumption and maintenance needs, ultimately leading to cost savings.

Lastly, the MST288 is the smaller model in the series, ideal for homes and small businesses. Despite its size, it does not compromise on efficiency. The MST288 features a straightforward design, ensuring ease of installation and maintenance. It utilizes a single-stage burner that provides consistent heat output, making it a reliable choice for low-demand applications. The unit is also equipped with adjustable settings, allowing users to tailor their heating needs effectively.

In summary, the Burnham MST series demonstrates a remarkable blend of innovation and practicality across its models. With features like advanced burner technology, efficient heat exchangers, and smart controls, the MST396, MST629, MST513, and MST288 cater to a wide range of heating needs while prioritizing energy efficiency and user comfort. These models stand out in the market, continually setting a standard for performance and reliability in heating solutions.
Top Page Image Contents