Hobart Commercial Dishwasher Error Code BOOSTER TEMP SENSOR: Open/Short

What does Hobart BOOSTER TEMP SENSOR - Service Required - OPEN mean?

The booster heats water to the final rinse temperature, and its probe lets the control confirm that it got there. If the probe circuit reads open or shorted, the display shows BOOSTER TEMP SENSOR / Service Required (Service Phone Number) / OPEN or SHORT. This message applies only to the LXeH and LXeR, which have the booster. The machine continues to run cycles, but without a valid booster temperature the control cannot check or regulate the rinse heat, and the final rinse may be too cool, which can show up as LOW RINSE TEMP. The manual's action is to call service, since the probe is part of the heating circuit inside the machine. The sensor message tells you the measuring probe is the problem, not necessarily the heater itself. In practice a technician first proves the probe against a thermometer, because a good heater with a bad probe looks the same on the display as a weak heater, and the repair is very different. Steam, heat cycling and mineral scale around the booster are the usual reasons these probes age.

Affected models and control systems

Hobart LXeH (ML-130192) and LXeR (ML-130194) only, the models with the booster.

Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.

What you may notice

• BOOSTER TEMP SENSOR Service Required on the display
• OPEN or SHORT beneath the message
• Rinse that feels cooler or inconsistent

Possible causes

Likely causes — what usually sits behind BOOSTER TEMP SENSOR - Service Required - OPEN on this control. A technician confirms which one it is before any part is replaced.

• Booster temperature probe out of range
• Probe lead damaged near the booster tank
• Corroded probe connector
• Probe element failing
• Scale around the probe seat

Safe checks before calling for service

How a technician diagnoses BOOSTER TEMP SENSOR - Service Required - OPEN

1. Confirm OPEN or SHORT from the display.
2. Measure the probe resistance and compare it with the maker's chart.
3. Inspect the probe lead, connector and seat for corrosion or scale.
4. Check the booster heater is not the real fault by measuring its current and rinse temperature.
5. Replace the probe or wiring and verify the rinse temperature.

How BOOSTER TEMP SENSOR - Service Required - OPEN differs from similar codes

BOOSTER TEMP SENSOR applies only to the LXeH and LXeR, whereas WASH and RINSE TEMP SENSOR messages apply across the LXe range.

Technical reference

Maker documentation

Hobart owner support

Edition

FORM 38435 (March 2014)

Models / control

LXeH, LXeR only

Section

DIAGNOSTIC/ERROR MESSAGES (page 27)

Checked

October 2026

We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.