TECHNICAL UPDATES

Troubleshooting probe style warewash dispensers

Probe style dispensers monitor the detergent concentration level in dishmachine wash tanks. Two settings determine the accuracy of the detergent control, the probe and the concentration.

Common technical questions for probe style warewash dispensers are:

1) Detergent feeds continuously,
2) Detergent pump (or solenoid) does not feed.

TROUBLESHOOT:

DETERGENT FEEDS CONTINUOUSLY
1: Check probe wiring connections at the circuit board and at the probe.
2: Perform a "Short Test". The detergent feed should stop when the following connections are "shorted".

Step A: Check the probe terminals at the circuit board. Take a piece of wire and short across the two screws where the probe is wired.

Results: Feed should stop. If the detergent feed does not stop, the circuit board may be bad.
Solution: Replace the board and reset the concentration.

Step B: Short the probe wire connections at the probe.

Results: Feed should stop. If the detergent feed does not stop, the probe wire may be bad.
Solution: Replace the wire.

Step C: Short the probe tips on the probe.

Results: Feed should stop. If the detergent feed does not stop, the probe may be bad.
Solution: Replace the probe.

If the detergent feed stops at each step then the problem could be hard water, high temperatures, or continuous fresh water fill diluting the chemical strength.

DETERGENT DOES NOT FEED
1: Check pump or solenoid wiring connections.
2: Disconnect one of the probe wires. This should start the detergent feed at the detergent feed cycle.

Step A: Start at the circuit board and disconnect one of the probe wires.

Results: Feed should start. If the detergent feed does not start, the circuit board may be bad.
Solution: Replace the circuit board.

Step B: Disconnect one of the probe wires at the probe.

Results: Feed should start. If the detergent feed does not start, the probe wire may be bad.
Solution: Replace the cable

Step C: If the detergent feed starts at each of the step above, the probe may be bad. Replace the probe.

If the problem persists, it could indicate a "floating" ground in the dishmachine. Make sure the probe is mounted below the water line near the recirculating pump intake, and 3-4 inches from the corners, heating elements or bottom of tank.