Whirlpool EDP/EDN SECTION Maintenance and Component Description, 7A. Unit Pump, 7B. Gas Valve

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The appliance will attempt to ignite three times, if ignition is not successful, the appliance will lock out and display [LO]. Ignition reset is done by pressing the reset button on top of the control panel. EBP models will then operate to heat the transfer tank.

7.EBP ONLY: Turn on a hot water tap. This puts the appliance in the DHW mode.

Caution

Should any pronounced odor of gas be detected, or if the gas burner does not appear to be functioning in a normal manner, close main shutoff valve, do not shut off switch, and contact your heating contractor, gas company, or factory representative.

You MUST check flame monitoring control (ignition system safety shut off device).

1.Close gas shutoff valve with burner operating.

2.The flame indicator light will go out and blower will continue to run for the post purge cycle. Three additional attempts to light will follow including pre-purge, ignitor on, valve/flame on and post purge. Ignition will not occur as the gas is off. The display will eventually show [LO] approximately 10 seconds after the gas valve has closed on the third ignition attempt.

3.Open gas shutoff valve. Press reset button on the top of the control panel. The ignition sequence will start again and the burner will start. The appliance will return to its previous mode of operation.

6D. Mode and On/Off Buttons Operation

The on/off button it is used to switch the

appliance from standby [ON] to standby [OFF] and vice versa. It is NOT an isolation switch. The mode button accesses all other functions as described in their particular sections of this manual.

SECTION 7.

Maintenance and Component

Description

7A. Unit Pump

The unit pump operates whenever there is a call for heat or hot water.

It is a wetted-rotor type pump and should always be filled with water when it is operating so that it will cool properly.

If a pump change is required for any reason, valve off the boiler and drain approximately 1 or 2

gallons (approx. 4-8L) of water from it. Turn off the main disconnect switch and unplug the pump wires, remove the pump motor. The pump housing need not be removed. The replacement pump motor should be installed in the reverse order from which the old pump motor was removed. After filling the system be sure the combustion chamber coil vents through the air vent located on top of the boiler chamber (inlet manifold extension).

7B. Gas Valve

The gas valve is a 24VDC solenoid operated, negative pressure regulated ratio valve. The outlet pressure may be adjusted as described in the service section. It is designed to operate with supply pressures of 4-13 inches w.c. (1.0 to 3.2 kPa). To remove the gas valve, shut off 120 volt power and the gas shutoff valve, remove the 4 screws on the upper and lower flanges and disconnect the wires from the gas valve, the valve may now be removed. After the valve has been removed, replace with a new valve in the reverse order in which the old valve was removed. Turn on gas shutoff valve and 120 volt power and check boiler operation and gas tightness of gas valve connections.

7C. Safety Limit Switch

The Safety Limit Switch is an automatic reset switch with a fixed set point of 230°F (110°C). To replace the switch, shut off the 120 volt power.

Disconnect the 2 wires from the quick connects at the switch and remove the switch. To replace, perform the same operations in reverse. Turn on disconnect switch and check boiler.

7D. Boiler Control Printed Circuit Board (PCB)

The Integrated Boiler Control Module controls the ignition process, the combustion process, the temperature of the boiler flow and return, and the transfer tank temperature* and provides both domestic hot water* and space heating on demand.

To do this it takes inputs from three temperature sensors, a domestic hot water flow switch, an overheat thermostat (safety limit) and an external space heating switch, such as a room thermostat, zone valve end switches or circulator relay contacts. It then controls the pump, blower, ignitor and gas valve sequencing.

It constantly displays the boiler outlet temperature when the appliance is operating in one of its demand modes. It also allows the user to obtain information from the appliance to determine the water temperature at three different locations within the appliance and to find up to 8 previous faults stored in memory.

If replacement of PCB is necessary, shut off the 120 volt power and disconnect the wire connectors from the pcb. Remove the PCB from its location posts.