AERCO CXT-E Retrofit Kit - Manual (Page 41)

ECS and CXT-E Retrofit Instructions Kit # 27004-TAB
Technical Instruction Document TID-0141_0A
12/30/2014 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 • Phone: 800-526-0288 Page 41 of 76
4.2.4 NPT Plugs
Each Retrofit Kit contains four NPT Plugs in the following sizes:
• 1/4 inch
• 1/2 inch
• 3/4 inch
• 1 inch
These plugs are installed in the remaining tapped holes in the Top Head where components used
with the previous Control System were installed. The location and size of the required Plugs may
vary depending on the specific AERCO Heater Model being retrofitted. Refer to Figure 2-1 for
reference.
Ensure that all tapped holes in the Top Head have been plugged before proceeding with the
installation.
4.3 FLOW METER INSTALLATION
As part of the Electronic Control System (ECS) Retrofit, a new Flow Meter must be added to the
Packaged Heater. The purpose of this meter is to provide a feed-forward signal to the
Temperature Controller contained in the ECS Control Box. The installation location will vary
depending on whether the AERCO Water Heater Model being retrofitted is a Helitherm Heat
Exchanger (A-Plus, B-Plus, B-Plus II and E-Plus), or a Water-to-Water Double-Wall Heat
Exchanger (WWDW-24, WWDW-45, WWDW-68). For Helitherm Model Heaters, the Flow Meter
is installed between the Cold Water Inlet and the Drain Outlet on the Bottom Head of the Heater
(Figures 4-5 and 4-6). However, for Water-to-Water Double Wall Heater Models, the Flow Meter is
installed between the Cold Water Inlet and Drain Outlet on the Heater Shell. See Figure 4-7. All
required installation components are included in the Retrofit Kit. Proceed to section 4.3.1
(Helitherm) or 4.3.2 (Water-to-Water Double-Wall), as applicable.
IMPORTANT
Prior to installing the inlet or outlet tubes to the Flow Meter (step 2 of
sections 4.3.1 and 4.3.2), it will be necessary to first temporarily remove
the strain relief assembly shown in Figure 4-8. After removal, perform the
following steps:
1. First, hand-tighten the inlet and outlet tube compression fittings to the
Flow Meter. Position the “flats” on the fitting to avoid interfering with
reinstallation of the strain relief in the next step.
2. Next, attach the strain relief to the Flow Meter cable (Figure 4-8).
3. After the strain relief is installed, fully tighten the inlet and outlet tube
compression fittings to the Flowmeter.