QUESTION:

To:  Shane

May 5th, 2010

Greetings,

I am writing concerning a replacement liquid level control board.  I recently replaced the liquid level control board on a Fetco 52H Coffee Brewer.  I replaced an older analog board with the new digital one.  I followed the schematics carefully and was sure to connect the wires to their proper terminals.  I connected the brown wire to the fill terminal, the black to the heat, the green to the liquid level probe, the orange to the L1 and the whites to the neutral, also I connected the single wire white wire bolted to the chassis to the common terminal.

However, when I turn on the machine I have a problem with the fill circuit.  The fill solenoid valve will engage for one second then shut off for two and then engage again and then so on.  I checked to make sure that there were no frayed wires or loose connections.  Also I made sure that the water sensitivity jumper is set for low.  When I look at the liquid level control board the red LED light indicating power to the board remains constant when the machine is turned on and the first yellow LED for fill turns on and off in synch with the engaging of the fill valve solenoid.

I am wondering if I have something connected incorrectly or if I am missing something else that is causing this machine to function improperly.  Any help with this matter will be most appreciated.

Regards,

Cameron

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ANSWER:

Cameron,

This is an interesting problem. The first thing I want to focus my attention since you seem to be wired correctly is on the board itself and the LED’s. You mentioned that the red LED is on when the power to the brewer is on which is exactly what it should be. You also mentioned that the first yellow LED turns on and off in sequence with the fill valve; this LED indicates power is being sent to the fill valve so this is normal.

What is not normal however is the valve turning on and off the way that it is. Assuming that the tank is not full and that the brewer is not brewing; so based on this can you tell me if you have ever seen a green LED come on at all? If the green light comes on when the yellow light goes out then somewhere in the system the liquid level circuit is showing full when the tank is not full.

Check this out and let me know what you find. One answer will lead to a bad board another will lead to a potential wiring issue.

 I hope this is helpful Information and I look forward to hearing back from you.

Shane Blais
Director of Technical Services & Corporate Training