Check Orifice Plate - Replace If Necessary - Williamson-Thermoflo GWC-070 Manual

GWC S 2
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Prepare the boiler
Check orifice plate — replace if necessary
correct orifice plate
The
will result in severe personal injury, death or substantial
property damage.
gas orifice plate. It MUST BE CONVERTED to use
propane.
Natural gas:
For natural gas installations,
marking
. It must be the same as the boiler size. If the orifice plate is
stamped with another size, obtain the correct plate from your whole-
saler. The boiler size is stamped where the "X" is shown in the plate
stamping, Figure 6.
Propane:
replace the silver gas/air orifice plate with
For propane installations,
the red/white plate
, per following instructions. Ensure the red/white
plate boiler size is correct for the GWC boiler being installed. The boiler
size is stamped where the "X" is shown in the plate stamping, Figure 6.
Also fill out the propane label in the conversion kit and attach to the
left side of the jacket, above the gas inlet opening, as shown in Figure 5.
Orifice plate installation, when required
Access the bottom of the blower housing as shown in Figure 5.
read the marking on the plate edge
To inspect the plate only,
must read the same as the boiler size and fuel, as follows:
Boiler model Natural gas marking
GWC-070 NG 3 SEC
GWC-105 NG 4 SEC
GWC-140 NG 5 SEC
GWC-175 NG 6 SEC
To replace the plate, using a
Figure 6:
1 2
1. Loosen screws and two full turns.
3 4
2. Remove screws and .
3. Pull the gas/air orifice plate forward to remove it.
4. Slide in the new plate as shown in Figure 6. The
propane plate must go next to the blower housing
3 4
5. Replace screws and . Tighten all four screws securely and uni-
DO NOT
formly. overtighten.
torque.
6. Bend down plate label tab at score mark as shown in lower right
corner of Figure 6, item 10.
DO NOT use electric or pneumatic screwdrivers to re-
move or tighten the gas/air boss screws. Hand-tighten
only, using manual screwdriver. Should the torque exceed
40 inch-pounds, the threaded holes could strip out,
causing an inadequate seal of the orifice plate. Failure to
properly seal the plate to the housing could result in a gas
leak, causing severe personal injury, death or substantial
property damage.
8
-
fired water boiler
(continued)
must be used. Failure to do so
The boiler is shipped with a natural
inspect the silver gas/air orifice plate
Propane marking
LP 3 SEC
LP 4 SEC
LP 5 SEC
LP 6 SEC
manual screwdriver or nut driver
red side of a
DO NOT
exceed 40 inch-pounds
— Boiler Manual
Figure 5
Check for correct gas orifice plate
A Remove jacket front
panel to access the bot-
tom side of the blower
housing.
B Complete the propane
conversion label includ-
ed with the conversion
kit. Install label on jacket
left side, as shown.
Leave the boiler on its back,
on the skid as shown, until
you have checked the gas/air
orifice plate and replace it if
necessary.
Figure 6 Follow instructions to check or replace
gas orifice plate ("X" = boiler size)
. It
, see
.
1–4 Screws — follow instructions for loosening and tightening
5
Gas/air manifold
6
Front section, bottom view, component details omitted
7
Side shown must point toward air inlet hose — WARNING
label side for natural gas; WHITE side for propane gas
8
Propane orifice plate, RED one side and WHITE on the
other (red side must face the blower housing
9
Natural gas orifice plate, SILVER
10
Orifice plate after bending along score mark — label is
visible when installed
Part number 550-142-786/0712