3 shell removal, 4 removal of coils and risers, Assembly preparation – AERCO Coil & Riser Replacement User Manual
Page 7: 1 preparation of bottom head, He-109

PR2: 04/01/11 Page 7 of 16
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288
Coil/Riser Replace Instructions for Helitherm Water Heaters
Technical instructions
TID-0038_0A
HE-109
5.3 Shell Removal
Remove the Heater Shell as follows:
5.4 Removal of Coils and Risers
The Coil Assemblies, Riser and Condensate Return are removed as follows:
6. Assembly Preparation
Prior to reassembling Heater components, the Bottom Head, Steam Riser, Condensate Return and Coils
must be cleaned, inspected and prepared as described in the following paragraphs:
6.1 Preparation of Bottom Head
The Bottom Head of the Heater must be cleaned, inspected and prepared for reassembly as follows:
Shell Removal
1) Using a black marker, mark the edge of the Heater Bottom Head flange and Shell flange in order to
indicate their correct relative positions upon reassemble. The Top Head can remain attached to the
Shell.
2) Using the 1-1/16” combination wrench, unbolt the sixteen studs and nuts around the bottom ring of the
Shell. The two nuts located in-line with the mounting skid legs are to be removed with the stud left in
place.
3) Attach a chain hoist to the two lifting lugs on the Top Head. Lift the Shell up to clear the internal coil
bundle.
4) Using a light source, visually inspect the inside of the Heater Shell for evidence of damage to the
Copper Shell Liner. If any area of the Copper Liner is damaged, replace the Shell down on the Bottom
Head and contact your local AERCO Representative to process return of the Heater to AERCO for
repair.
5) Move the heat exchanger bundle a few feet to the side so that the Shell can be lowered to the floor.
Set the Shell on clean surface. Use care to avoid damaging the bottom edge of the Copper Shell Liner.
Section 5.3 Instructions
END
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Removal of Coils and Risers
1) Using the proper size open-end wrench, loosen the two Union Nuts securing the Coils to the Steam
Riser and Condensate Return.
2) Using a pipe wrench, remove the Steam Riser and Condensate Return from the Bottom Head.
Section 5.4 Instructions
END
Preparation of Bottom Head
1) Clean off all debris from the topside of the Bottom Head.
2) Visually inspect the internal pipe threads where the Risers are connected. The overall depth of
threads should measure, (1-1/8” for 2” NPT and 1” for 1” NPT)
3) If the threads are less then the required depth, use the appropriate 1” or 2” NPT tap to clean out the
threads.
4) Using the gasket removal tool, remove the Shell Gasket from the Bottom Head. Use care to avoid
creating scratches or indents in the Bottom Head casting’s gasket surface area. Any linear scratches
can potentially create a leak.
5) Apply pipe dope to the internal NPT threads in the Bottom Head.
Section 6.1 Instructions
END