Bunn TU3 service manual SERVICE cont, Brew Solenoid Valve, solenoid valve

SERVICE (cont.)	If continuity is not present as described, replace the
BREW SOLENOID VALVE	solenoid valve.

			6.	Check the solenoid valve for coil action. Connect
				the brewer to the power source. With ON/OFF
				switch in the "ON" upper position press start switch
				and listen carefully in the vicinity of the solenoid
				valve for a "clicking" sound		as the coil magnet
				attracts.
			7.	Disconnect the brewer from the power source.
			If the sound is heard as described and water will not
			pass through the solenoid valve, there may be a block-
			age in the water line before the solenoid valve or, the
			solenoid valve may require inspection for wear, and
			removal of waterborne particles.
			If the sound is not heard as described, replace the
			solenoid valve.
	FIG. 2 BREW SOLENOID VALVE	P1277.40	Removal and Replacement:
			1.	Remove all wires from solenoid valves.
Location:			2.	Turn off the water supply to the brewer.
	Viewing the brewer from the rear the brew sole-		3.	Disconnect the water lines to and from the sole-
noid valve is mounted on the left side of the mounting				noid valves.
bracket.			4.	Remove the two #8-32 keps nuts holding the
				mounting bracket to the brewer base.
Test Procedures:			5.	Lift out the bracket.
1. Disconnect the brewer from the power source.			6.	Remove the two #10-32 slotted-head screws hold-
2. Disconnect the white/violet and white/green wires				ing the solenoid valve to the mounting bracket.
	from the solenoid valve. With the ON/OFF switch		7.	Securely install the new solenoid valve to the
	in the "ON" upper position press the start switch.			mounting bracket.
3.	With a voltmeter, check the voltage across the		8.	Attach the mounting bracket to the brewer base.
	white/violet and white/green wires. Connect the		9.	Securely fasten the water lines to and from the
	brewer to the power source. The indication must			solenoid valves.
	be:		10.	Refer to the Fig.3 when reconnecting the wires
	a) 120 volts ac for two wire 120 volt models.
	b) 240 volts ac for two wire 240 volt models.		WHI/VIO to Dilution WHI/GRN to
	c) 100 volts ac for two wire 100 volt models.
			Solenoid
4. Disconnect the brewer from the power source,				Brew Timer TL4	WHI/VIO to Brew Solenoid
					WHI/VIO to Brew Timer TL1
If voltage is present as described, proceed to #5					WHI/BLU to Dilution
If voltage is not present as described, refer to Wiring					Timer TL4
Diagrams and check brewer wiring harness.			BREW			WHI/VIO to Dilution
			SOLENOID			Solenoid

5. Check for continuity across the solenoid valve coil	DILUTION	BRN/WHI to Selector
terminals.		Switch
	SOLENOID
If continuity is present as described, reconnect the		SWEETENER
white/violet from the ON/OFF switch and white/green		SOLENOID (Optional)
				P1278
wire from the brew timer.	FIG.3 SOLENOID VALVE TERMINALS
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