Page 48 | BRADFORD WHITE CORP. |
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11.2.6 Transformer with Integral Circuit Breaker
The appliance has a 24Vac transformer with integral 4 amp circuit breaker installed for supplying the control voltage required for the appliance only. The transformer is sized for the appliance load only and should not be used to supply power to additional field devices. If additional loads are added or a short occurs during installation the integral circuit breaker may trip. If this happens make sure to reset the circuit breaker prior to replacing the transformer.
Depending upon the revision of the appliance the transformer may be mounted to the back or underneath the control panel. In either case, if the transformer must be replaced turn off the 120Vac power to the appliance. Remove the transformer wires from terminal blocks.
Remove the fasteners holding the transformer and remove the transformer. Replace with a new transformer in reverse order.
If the transformer is replaced with parts other than the OEM transformer, be sure to add circuit protection if it is not integral to the new transformer.
WARNING
Failure to include proper circuit protection may lead to premature component failure, fire, injury or death.
11.2.7 Blower
The combustion air blower is a
11.2.8 Heat Exchanger Coils
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 and 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 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 burner door at the front of the boiler, and inspect the tubing using 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 120 Volt power supply to the boiler
2.Turn off all manual gas valves connecting the boiler to the main gas supply line.
3.For NT 600 models only (all other sizes please skip to step four). NT 600 models will require the gas valve to be removed in order to remove the burner door. To do this, remove the wire connections from the gas valve. Remove the flange bolts from the gas supply pipe connected to the gas valve (1B). Remove the flange bolts connecting the gas train to the venturi (1A). Remove the gas train assembly keeping gaskets and
4.Remove the four bolts connecting the blower flange to the burner door arm.
5.Remove the nuts located on the outside diameter of the burner door to the heat exchanger.
6.Remove the burner door/burner assembly from the heat exchanger.
7.Disconnect the condensate drain line.
8.Attach a longer hose to drain and run to a bucket.
9.Clean the heat exchanger by brushing light accumulations of soot and debris. Use a brush with soft bristle (non metal) to avoid damaging the surface of the heat exchanger tubes.
10.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.
11.Install all components removed in the reverse order to place the appliance back in operation. Make sure all gaskets are in place as components are installed. Replace any damaged gaskets. Do NOT reuse damaged gaskets.
12.Place the appliance in operation according to Section 10 checking all gas connections for leaks. Confirm all fasteners are tight.
