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Undersized expansion tanks cause system water to be lost from the relief valve, causing make-up water
to be added. Eventual boiler failure can result due to excessive make-up water addition.
SUCH FAILURE
IS NOT COVERED BY WARRANTY.
2. The expansion tank must be located as shown in Part 4, Boiler Piping Details, or following recognized
design methods. See expansion tank manufacturer’s instructions for details. Always install an expansion
tank designed for potable water systems.
3. Connect the expansion tank to the air separator only if the separator is on the suction side of the
circulator. Always install the system fill connection at the same point as the expansion tank connection to
the system.
4. Most chilled water systems are piped using a closed type expansion tank.
DIAPHRAGM (OR BLADDER) EXPANSION TANK
Always install an automatic air vent on top of the air separator to remove residual air from the system.
E. CIRCULATORS
DO NOT
install automatic air vents on closed type expansion tank systems. Air must remain in the system
and return to the tank to provide an air cushion. An automatic air vent would cause air to leave the
system, resulting in improper operation of the expansion tank.
DO NOT
use the boiler circulator in any location other than the ones shown in this manual. The boiler
circulator location is selected to ensure adequate flow through the boiler. Failure to comply with this
caution could result in unreliable performance and nuisance shutdowns from insufficient flow.
SIZING SPACE HEAT SYSTEM PIPING
1. In all diagrams, the space heating system is isolated from the boiler loop by the primary/secondary
connection.
2. Size the piping and components in the space heating system using recognized design methods.
F. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE BOILERS
The boiler is designed to function in a closed loop hydronic system. The included temperature and
pressure gauge allows the user to monitor system pressure and outlet temperature from the boiler. It is
important to note that the boiler has a minimal amount of pressure drop that must be calculated when
sizing the circulators. Each boiler installation must have an air elimination device that will remove air from
the system.
Install the boiler so the gas ignition system components are protected from water (dripping, spraying,
etc.). Allow clearance for basic service of the boiler circulator, valves, and other components. Observe
minimum 1” clearance around all uninsulated hot water pipes when openings around pipes are not
protected by non-combustible materials.
On a boiler installed above radiation level, some states and local codes require a low water cut off device.
This is provided standard on the Mod Con boiler. Check with local codes for additional requirements. If
Summary of Contents for Mod Con 300 HL
Page 13: ...13 Figure 2 ...
Page 31: ...31 Figure 13 ...
Page 37: ...37 J SIDEWALL VENTING DIAGRAMS Figure 16 Sidewall Venting with Tee and Coupling ...
Page 38: ...38 Figure 17 Sidewall Venting Diagrams ...
Page 39: ...39 K VERTICAL VENTING DIAGRAMS Figure 18 Two Pipe Roof Venting with Tee and Coupling ...
Page 40: ...40 Figure 19 Roof and Sidewall Venting with Stainless Steel ...
Page 44: ...44 E GAS VALVE Figure 21 ...
Page 45: ...45 Figure 22 ...
Page 55: ...55 Figure 28 Mod Con Internal Connection Diagram ...
Page 73: ...73 Figure 32 ...
Page 74: ...74 Figure 33 ...
Page 75: ...75 Figure 34 ...
Page 76: ...76 Figure 35 ...
Page 77: ...77 Figure 36 ...
Page 80: ...80 ...
Page 81: ...81 ...
Page 82: ...82 MAINTENANCE NOTES ...
