COZY WOW253 Installation And Operating Instructions Manual page 21

TO REMOVE COMBUSTION TUBE ASSEMBLY FOR
INSPECTION, CLEANING AND REPLACEMENT
SERVICE MUST BE PERFORMED BY A
QUALIFIED SERVICE AGENCY.
A.) Turn thermostat to "OFF" or lowest
setting. Allow heater to cool.
B.) Turn off electric power to heater.
C.) Remove front panel.
D.) Turn gas supply valve to "OFF".
E.) Disconnect gas supply line from gas valve.
F.) From outside, remove six (6) screws
securing back of outer cabinet to air in
take and exhaust flanges. (See Figure 5).
G.) From inside, gently slide combustion tube
assembly forward and out of outer
cabinet. (See Figure 6).
H.) Disconnect air pressure switch tubing
from draft inducer. (See Figure 18-B).
I.) Remove draft inducer. (See Figure 18-B).
J.) Disconnect ignition cable and pressure
switch tubing from top of burner box.
(See Figure 16).
K.) Remove screws securing collection box
flange and burner box flange to inner
casing top, bottom, and back.
(See Figure 19).
L.) Pull combustion tube assembly forward
and out. (See Figure 20).
M.) You can now inspect, clean or replace
tubular heat exchanger as needed.
NOTE: If combustion tube assembly is
being replaced, you must keep and use
collection box and burner box from
assembly being replaced.
N.) Carefully check integrity of all gaskets
(replace as needed), then reinstall combustion
tube assembly by reversing Steps L - A.
Follow lighting instructions to put heater in
operation.
FIGURE 19
For WOW403 / WOW404
IGNITOR
CABLE
IGNITOR
Circulating
Blower #2
Circuit
Board
Transformer
Junction
Box
Air Intake
FIGURE 18-B
Page 21
PRESSURE
S W I T C H
TUBING
FIGURE 16
Pressure
Switch
(For WOW403 / WOW404)
FIGURE 20
BURNER
BOX
Draft
Inducer
Liner
Circulating
Blower #1