Field controls CAS-2WM User Manual

COMBUSTION AIR SYSTEM

Model: CAS-2WM

WEIL-MCLAIN OUTSIDE AIR KIT

FOR USE WITH OIL BURNER MODELS QB-180 & QB-300

4” VRV

AIR BOOT™

4” IAH HOOD

The Air Boot™ model CAS-2WM is for use only on the designated burner(s) as
described in these instructions only when the specific burner includes this Air Boot™
when shipped from the burner manufacturer or where the burner instructions
specifically reference the model CAS-2WM Air Boot™ as an optional air intake
system.

ITEMS INCLUDED IN KIT: INSTALLER SUPPLIED ITEMS:

1 - Air Boot™ Air Duct Pipe and Elbows as needed
1 - 4” VRV (Vacuum Relief Valve) -use 4” Dryer Venter, Aluminum or
1 - 4” IAH Hood Galvanized Steel
1 - Set of Gaskets ¼” NPT 90° street ell for oil line if needed
1 - Burner Coupling Set Exterior rated caulk, silicone sealant or
2 - Mounting Bolts equivalent

THE PURPOSE OF THE VACUUM RELIEF VALVE (VRV)

Figure 1

Rotate Oil Solenoid valve and realign 90° fitting as
shown below. Do not reconnect the oil line as in E

The vacuum relief valve provides combustion air to the burner
if the outside air supply is interrupted for any reason. Typical
situations would be blockage of the air intake or duct, or wind
effect which cause a negative pressure at the air intake hood.

VRV OPERATION

With normal air flow through the air intake hood and duct, the
VRV stays closed. All combustion air comes in through the air
duct. If the pressure in the Air Boot™ drops, the valve door
opens. Room air flows in through the VRV to provide the air
needed for combustion. When the Air Boot™ pressure returns
to normal, the VRV closes.

WARNING: This symbol is used in these instructions
to indicate presence of hazards, which can cause
severe personal injury, death or substantial property
damage.

WARNING: Failure to perform the following can cause
severe personal injury, death or substantial property
damage:

• Read all instructions before starting

• Follow all instructions in proper order

• Turn off service switch on boiler and any other
electrical disconnect switches

• Turn off the fuel supply valve(s) and disconnect fuel lines from the
burner

and F until you have installed the Air Boot™

INSTALLATION

1. Rotate the burner oil solenoid valve as shown in Figure 1, steps A-D. Do
not reconnect the oil line (per E-F). The solenoid valve must be aligned as
shown to prevent interference with the Air Boot™.

2. Remove the two ¼” bolts holding the oil pump to the burner housing.
Remove the oil pump.

3. Remove the screw which holds the air band to the housing. Remove the
air band.

4. Install the sealing gaskets onto the burner housing (See Figure 2).

5. Install mounting spacer onto Air Boot™ (See Figure 3).

6. Place the Air Boot™ on the housing, through the large opening in the back
side of the Air Boot™ (See Figure 3). Press the Air Boot™ into position
and align roughly plumb with the burner. Align the Air Boot™ mounting
holes with the burner oil pump mounting holes.

NOTE: Replace pump coupling with the coupling supplied with kit.

7. Now put the oil pump and the AirBoot™ kit coupling back into place.
Replace the two ¼” oil pump mounting screws. Tighten the screws.

8. Reconnect the burner oil line to the ell fitting on the oil pump per Figure 1,
drawings E and F.

Figure 2

Figure 3

Page 2

Figure 4