AERCO Coil & Riser Replacement - Manual (Page 5)

PR2: 04/01/11 Page 5 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. Heater Isolation and Disassembly
5.1 Isolating Heater
To isolate the Heater from all facility energy sources (steam, water, electrical, etc.), proceed as follows:
NOTE
The procedures in the following paragraphs are arranged to isolate, disconnect and
disassemble the unit to the extent necessary to repair or replace defective items. These
procedures should be performed in the order specified to minimize repair time.
Isolating the Heater
1) Disconnect and Lock-Out/Tag-Out external AC power supplied to the Control Box and any other
devices connected to the Heater.
2) Using a voltmeter, check to ensure that all incoming voltage readings are zero Before continuing.
3) If the Heater is equipped with a Pneumatic Steam Valve, close the valve supplying air inlet
pressure to the Pneumatic Controller.
4) Close all stop valves in the Steam Inlet and Condensate Outlet lines
5) On the water-side, close the stop valves in the following order:
• Hot water outlet line
• Recirculation line
• Cold water inlet line
6) Carefully open the Relief Valve located on the Top Head to relieve pressure in the Heater Shell.
Water should stop flowing from the valve within one minute. If water continues to flow from the
Relief Valve, one of the water stop valves is not securely closed.
7) While holding the Relief Valve open to prevent creating a vacuum in the Shell, open the Drain
Valve in the Bottom Head on the Heater. Completely drain the potable water from the Heater.
Section 5.1 Instructions
END