AERCO ECS Upgrade for SW Double Wall Heaters - Manual (Page 7)

ECS Upgrade for SW Double Wall Heaters, Kits 27035, 27036, 27037
Technical Instruction Document TID-0142_0A
12/30/2014 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 Page 7 of 24
2.1 Isolating Water Heater
To isolate the Water Heater from all facility energy sources (steam, water, electrical power),
proceed as follows:
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 Control Valve Actuator, close the valve supplying
air inlet pressure to the Pneumatic Controller.
4. Close all stop valves in the Steam Inlet and Condensate Outlet lines. On water-to-water
systems, do not rely on the Boiler Water Out Check Valve to stop the flow of water.
5. On the water-side, close the stop valves in the following order:
(a) Hot water outlet line
(b) Recirculation line
(c) 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.
2.2 Draining Water Heater
Allow the unit to cool sufficiently prior to draining the unit. When sufficiently cooled, drain as
follows:
1. After ensuring there is no pressure build-up in the Heater Shell (section. 2.1, step 6), block
open the Relief Valve in the Top Head to avoid creating a vacuum in the Heater Shell when
it is drained.
2. Open the Drain Ball Valve in the Bottom Head and allow the potable water in the Heater
Shell to drain completely. If the unit is a Water-to-Water Double-Wall Heater (WWDW-24,
WWDW-45 or WWDW-68), the Drain is located on the Shell and may either be plugged with
a 3/4” NPT Plug or equipped with a Ball Valve and additional drain piping. Remove Plug or
open Drain Ball Valve as applicable.
CAUTION
DO NOT DISCARD ANY OF THE REMOVED PARTS OR ASSEMBLIES
UNLESS IT IS SPECIFICALLY INDICATED THAT THEY WILL NO
LONGER BE USED. IT IS RECOMMENDED THAT ALL REQUIRED
ITEMS BE REMOVED AS INDICATED IN THE FOLLOWING STEPS
PRIOR TO PERFORMING ANY OF THEREPLACEMENT
PROCEDURES IN SECTION 3.
2.3 Removal of Hot Water Outlet Piping
Disconnect the union and any external piping connected to the flange in the hot water outlet
piping (located beyond the outside diameter of the Top Head).