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Heater isolation and disassembly, 1 isolating heater, He-109 – AERCO Coil & Riser Replacement User Manual

Page 5

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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