AIR HOSE | CONTROL SYSTEM |
The air hose is used to provide a flexible air path from the blower to the burner assembly. It is held in place with two standard hose clamps, see Figure 10.
The control system is comprised of an Outdoor Interface Module that monitors the functions of the WR ignition system, pressure switches, low water cutoff and temperatures in the tank.
FIGURE 10
FLUE ADAPTER |
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The flue adapter is made of a flat metal plate with an exhaust |
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adapter to mate with the exhaust elbow. This is where the flue |
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gases exit the heat exchanger. This is a very hot region and is |
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covered with a layer of high temperature fiberglass insulation, see |
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Figure 11. | FIGURE 13 |
FIGURE 11
EXHAUST VENT
The exhaust vent elbow mates with the flue adapter. The elbow mates with the exhaust terminal to dispose the flue gases to the outdoors. This venting section is covered with a fiberglass insulated wrap to protect from heat and condensation. These pipes are sealed with a high temperature gasket integral to the vent pipe fittings, see Figure 12.
FIGURE 12
BLOCKED OUTLET SWITCH
The Blocked Outlet Switch is set up to shut the unit off when a pressure buildup in the exhaust vent pipe occurs. This switch is a positive pressure switch that requires an increase in pressure to change the electrical contacts from normally closed to open. When this switch prevents the unit from igniting, most likely the exhaust is blocked. Check for obstructions in the exhaust venting and exhaust vent terminal, see Figure 14.
BLOCKED INLET/PROVER SWITCH
The Blocked Inlet/Prover Switch is set up to shut the unit off when a reduction in pressure in the intake vent occurs. This switch is a negative pressure switch that requires an increase in negative pressure to change the electrical contacts from normally open to closed. The switch is connected to the pressure tap connected to the housing of the blower. When this switch prevents the unit from ignition, most likely the intake is blocked. Check for obstructions in the inlet vent terminal, see Figure 14.
FIGURE 14
The blocked Inlet/Prover Switch has a second function. It is provided on the heater to verify that the fan is operating. When the fan increases in negative pressure, the electrical contacts close signaling that the blower is operational and is at peak performance. The controller requires that the electrical contacts on the switch close before it will allow the blower to come on.
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