Manifold Assembly (Supplied) - Watts AERCO MLX EXT 321 Installation, Operation & Maintenance Manual

Modulex Light Commericial Series
CHAPTER 4: Installation Instructions
On older models (MLX EXT 321, 481, 641, 802, 962,1123), the Pressure Relief Valve is not
factory installed, but instead included separately in the shipping container. It must be fitted on
the CSD-1 manifold at the site, per the instructions in the next section, 4.14 (see Figure 4-17).
3/4" PRESSURE RELIEF VALVE
Figure 4-16: 3/4" Pressure Relief Valve & Factory Installation – Newer Models
4.14 CSD-1 MANIFOLD ASSEMBLY (SUPPLIED)
The installation of a flow switch and pressure/temperature gauge are required. A 3/4" Pressure
Relief Valve designed for the boiler output capacity must also be installed:
•
On newer models (MLX EXT 450, 600, 800 ,1100) with aluminum headers, the 3/4"
Pressure Relief Valve is pre-installed inside the boiler chassis at the factory, as shown in
Figure 4-16, above.
•
On older models (MLX EXT 321, 481, 641, 802, 962,1123) the 3/4" Pressure Relief
Valve must be installed at the site (see Step 4).
These components are supplied with the boiler and must be assembled and wired when the
boiler is installed at the site. The manifold components are shown installed into the CSD-1
manifold in Figure 4-17. The manifold assembly components supplied are:
•
3/4" Pressure Relief Valve – must be installed on older models only
•
Flow Switch
•
Pressure/Temperature Gauge
NEWER MODELS
Figure 4-17: CSD-1 Manifold Assembly and Components
OMM-0087_J • GF-143 • 11/17/2020
ST
1 DISCHARGE PIPE
ND
2 DISCHARGE PIPE
(Must Be Installed On-Site)
FLOW SWITCH
PRESSURE/
TEMPERATURE
GAUGE
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
3/4" PRESSURE RELIEF VALVE
OLDER MODELS
Page 43 of 150