Crown Boiler 24-10, 24-11, 24-08, 24-12 BMounting Elevations M&M 150, 64 Float Low Water Cut-offs

Page 41

“A”

M.CONNECT TANKLESS HEATER PIPING as shown in Figure 38. See Table IV for Tankless Heater Ratings.

NOTICE

The following guidelines should be followed when piping the tankless heater:

1.Install Flow Regulator

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. Refer to Figure 36 for piping recommendations. Locate the flow regulator below the inlet (cold water side) of the heater and a minimum of 36” away from the inlet so that the regulator is not subjected to excess temperatures during “off” periods when it is possible for heat to be conducted back through the supply line. The flow regulator will limit the flow of supply water regardless of inlet pressure variations ranging from 20 to 125 psi.

2.Install Water Temperature Mixing Valve

Refer to Figure 38 for piping recommendations. Adjust and maintain the mixing valve in accordance with manufacturer’s instructions.

Installation of a mixing valve will also lengthen the delivery of the available hot water by mixing some

WARNING

Install a mixing valve at the tankless heater outlet to avoid risk of burns or scalding due to excessively hot water at fixtures. Do not operate the boiler when equipped with a tankless heater unless mixing valve is operating properly.

L.W.C.O.

Application

Cut-Off Height

"A"

"B"

 

 

67

Primary or Secondary

35-1/2"

-

64

Primary (Gravity Return)

-

37-1/2"

150

Primary (Pumped Return)

-

40"

Figure 36:

“B”Mounting Elevations

of M&M 150, 64 and 67

Float Low Water Cut-offs.

cold water with the hot. In addition, savings of hot water will be achieved since the user will not waste as much hot water while seeking desired 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. An electric hot water booster can also be used. The mixing valve should be “trapped” by installing it below the cold water inlet to heater to prevent lime formation in the valve.

3.Flushing of Heater

All water contains some sediment which settles on the inside of the coil. Consequently, the heater should be periodically backwashed. This is accomplished by installing hose bibs as illustrated in Figure 38 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.

CAUTION

Do not operate tankless heater with hard water. Tankless failure will result. Install water softener if hard water is present.

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Contents Series Page Important Information Read Carefully Page Page Table of Contents Table of Contents Section I General Information Boiler RATINGS/DATA Locate the Unit Section I General InformationChimney or Vent Boiler FoundationVents Faults & Suggestions Assembly of Sections Manual DRAW- UP Section II Cast Iron Block AssemblyNipple Gauge Series 24 Section Arrangement Draw-Up Rods Alternating Pattern Manual Draw-up Center Section Channel Block Position Partial Block Draw-Up Hydraulic Draw-Up of Sections Canopy with Rear Flue Outlet Damper Assembly Section III Installation InstructionsBare Boiler Assembly Avoid Breathing Fiber Particulates and Dust Left Side Canopy Intermediate Bracket Inspect ALL Boiler Seals Mount Rear Observation Port Cover Refer to FigureSeries 24 Jacket Assembly Boiler Models 24-03 thru Mount Burner Adapter Plate to Burner Mounting Plate Burner Mounting Plate Refer to Figures 16Purpose of Tappings Steam Boilers Steam Trim Steam Boilers Install Steam Trim This Is Intentionally Left Blank Purpose of Tappings Water Boilers Water Trim Boiler Piping Heating Applications Water Boilers Install Water TrimBurner Installation Page Parallel Piping Conversion Recommendation 1 Use when Recommendation 2 Use when Recommendation 3 Use when Page Page Page BMounting Elevations M&M 150, 64 Float Low Water Cut-offs Schematic Tankless Heater Piping 24-08 24-09 CCW Open to System Return Temperature Control and ComponentsWater Boiler Pressure Relief Valve Hook-Up Typical Boiler Wiring with RTC Front Typical Boiler with RTC Return Sensor Rear Section IV Operating Instructions Always Inspect Installation BeforeStarting Burner Fill Heating System with WaterFlame Failure Boil MIN Delay Check Operation of High Limit Control Test ControlsBoiler and System Cleaning Steam Boiler Boiler and System Cleaning Water Boilers Oxygen Corrosion Frequent Water AdditionClean the Boiler Flueways Section V Service InstructionsMaintenance of LOW Water Cutoff Devices Operation General Maintenance ConsiderationsOIL Burners Section VI Burner SpecificationsSection VII Repair Parts & Carton Contents Series 24 Master Parts List Section VII Repair Parts Jacket Carton Bare Boiler Assembly Section Joiner Carton Assy Rear Target Wall Carton Standard Steam Trim Carton Assy RTC Carton with Outdoor Reset Tankless Coil Components Boiler Water Section Viii Appendix Page Mechanical Page Mechanical Electrical Page Page Page Page Page Page Page Page Series 24 Boiler Circulator Selection Taco 20F Differential Boiler Recirculation Grundfos Circulating Pump Way Boiler Recirculation Bell and Gossett Circulating Pump Way Boiler Recirculation Armstrong Circulating Pump Way Application Appendix C Valve and Actuator Mounting InstructionsService Record PN 980417 S24 12/05
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