Page 72
B
RADFORD
W
HITE
the blower to the adapter plate. If the fan is
determined to be defective, replace the existing
fan with a new one by reversing the steps
listed above. Be sure to install all the required
gaskets and o-rings between blower, adapter
plate, and Fuel/Air mixer.
11.2.8 Heat Exchanger Tubes
Black carbon soot buildup on the external
surfaces of the heat exchanger is caused
by one or more of the following; incomplete
combustion, combustion air problems, venting
problems or heater short cycling. Soot buildup
or other debris on the heat exchanger may
restrict the flue passages.
If black carbon soot buildup on the heat
exchanger is suspected, disconnect the
electrical supply to the unit, and turn off the
gas supply by closing the manual gas valve on
the unit. Access the heat exchanger through
the heat exchanger shrouds. Removal of
the outer baffles may be required for proper
inspection. Use a flashlight. If there is a buildup
of black carbon soot or other debris on the heat
exchanger, clean per the following:
Caution
Black carbon soot buildup on a dirty heat
exchanger can be ignited by a random spark
or flame. To prevent this from happening,
dampen the soot deposits with a wet brush
or fine water spray before servicing the heat
exchanger.
1. Shut off the Main power supply to the
boiler.
2. Turn off all manual gas valves connecting
the boiler to the main gas supply line.
3. Remove the blower assembly and burner
from the heat exchanger.
4. Disconnect the condensate drain line.
5. Attach a longer hose to the drain and run it
to a bucket.
6. Clean the heat exchanger by brushing
away any light accumulations of soot and
debris. Use a non metallic brush with soft
bristles to avoid damaging the surfaces of
the heat exchanger tubes.
7. Once the tubes have been brushed clean,
rinse the tubes and combustion chamber
with a small amount of water to rinse all
of the debris out of the bottom of the flue
collector and into the longer condensate
trap line, which is being diverted into a
separate container.
Note -
The Warranty does not cover damage
caused by lack of required maintenance, lack of
water flow, or improper operating practices.
WARNING
Failure to rinse the debris from the heat
exchanger and temporary drain line may
lead to clogged condensate lines, traps
and neutralizers. Condensate pumps
(if used) may also be damaged from
the debris left behind, possibly causing
property damage.
8. To place the unit back in operation, install
all removed components in the reverse
order. Be sure all gaskets are in place as
the components are installed. Replace any
damaged gaskets. Do
not
reuse damaged
gaskets.
9. Place the appliance in operation according
to Section 9, checking all gas connections
for leaks. Confirm all fasteners are tight.
11.2.9 Gas Pressure Switches
The high and low gas pressure switches are
120 Volt manual reset switches that act to cut
power to the interlock circuit if the gas pressure
is too low or too high for proper operation.
The gas pressure switches used are integrally
vent limited, and do not require venting to
atmosphere. To remove a switch, remove the
screw on the plastic housing and pull the clear
cover off. Disconnect the three wires from the
screw terminals. Twist the switch off the pipe
nipple. Reassemble in reverse order.
Set the low gas pressure switch to 3” w.c.
Set the high gas pressure switch to 15”w.c..”
