What does Hobart dishwasher fault code F3 mean and how do I fix it?

F3 (and the closely related F4) is a fuse on the Hobart AM16 control board that protects the 120 VAC supply to the control circuitry. When F3 opens, the display goes completely dark, no buttons respond, and the machine will not fill or wash. The blown fuse is almost always a symptom — not the cause — so simply replacing F3 without finding the underlying short usually pops the new fuse on power-up. Diagnostic flow: confirm line voltage at the supply terminal block, lock out power, remove F3 and F4 and ohm them for continuity, check transformer T1 for 120 VAC output (a shorted T1 will keep blowing fuses), and inspect every wire harness routed to the control board for chafing or pinched insulation. Replace only with the identical-rated fuse stamped on the original. If the new F3 blows again, stop and call Hobart Service — a shorted contactor or control board is likely.

What does Hobart dishwasher fault code F1 mean?

F1 is a fuse on the Hobart AM16 relay board that protects the 24 VDC control signal to the built-in chemical pumps (detergent, rinse aid, sanitizer). When F1 opens, the chemical pumps stop dosing entirely — the machine still washes and rinses mechanically, but ware comes out unclean and unsanitized because no detergent or sanitizer is being injected. Companion chemical-low codes 074, 075, 076, 077, and 079 may also appear on the display because the control no longer sees pump activation. Diagnostic flow: lock out power, ohm F1 for continuity, inspect each chemical pump wiring connector for corrosion (chemical splash causes resistance that pops fuses), measure 24 VDC at power supply PS1, and confirm the machine-type and chemical-pump parameters in the service menu match the installed configuration. If F1 blows again during a manual prime cycle, isolate each pump motor individually — the failed motor is the one that pops the fuse.

What does Hobart E4 mean on a dishwasher?

E4 on Hobart AM-series dishwashers is a tank-fill or water-level fault — the controller did not see the tank reach the fill probe or pressure switch within the allowed timeout. Confirm the inlet water supply is open and the building hot-water line is at pressure (Hobart machines need 20–90 psi dynamic, 110°–140 °F supply on most models). Inspect the inlet solenoid valve strainer for scale and debris, check the fill float or pressure switch hose for kinks and mineral blockage, and verify the drain ball is fully closed (a drain leaking under-tank will fool the controller into a perpetual fill state). On AM16 ventless and AM15VLF spec-sheet machines, E4 is also referenced as a layout dimension on the spec sheet (P6, P1, E4 callouts) — do not confuse the spec-sheet measurement reference with the runtime fault. The runtime fault clears with a power cycle once tank fill completes successfully.

What does PUMPDRN mean on a Hobart dishwasher?

PUMPDRN is not a fault — it is the normal Hobart status display shown while the drain pump is running, typically at end-of-cycle, between rack changes on conveyor machines, or when the machine is purging the wash tank. The display reverts to READY automatically once the pump completes the drain. PUMPDRN becomes a problem only when it gets stuck on (drain pump runs continuously and never finishes) or when the machine tries to start a wash and immediately reverts to PUMPDRN. Common stuck-PUMPDRN causes: drain ball or drain line clogged with food debris and rags; drain pump impeller jammed or motor failed; drain solenoid valve stuck open; or float switch in the wash tank reading wet when the tank is empty. Lock out power, pull the drain trap, clear blockage, and verify the drain ball seats fully before running the next cycle.

How do I read Hobart dishwasher fault codes and where is the fault log?

On AM16 and similar Hobart digital-control dishwashers, fault codes display directly on the machine's HMI (the small screen above the start buttons) when a fault occurs — the code number flashes alongside a brief description. To pull the historical fault log, enter the Manager Menu by holding the menu button for the documented duration (typically 3–5 seconds, per the AM16 Customer Support Manual page 66 service menu procedure) and navigate to the error history. Older Hobart machines without a digital display use status lamps and a binder-pocket service decal on the inside of the front panel that maps lamp patterns to fault categories. For machines with no HMI at all, fault diagnosis works backward from observable symptoms (no fill, no drain, no heat) using the Customer Support Manual's symptom-to-component table. Photographing the live error code is recommended before clearing it — once a power cycle clears the display, the technician on the next call has nothing to work from.

How do I reset a Hobart dishwasher after a fault code?

Most Hobart fault codes clear with a controlled power cycle once the underlying cause is fixed. Procedure: press the power button for 5 seconds (this drains the wash tank and shuts the machine down cleanly — do not yank the disconnect with a full hot tank), wait 10 seconds, and turn power back on. The machine should re-fill, heat, and return to READY. Latched-safety faults are different: a thermal cutout on the booster heater requires a manual reset button push at the heater itself after the water cools, and a blown F1 or F3 fuse requires physical fuse replacement before the machine will operate. Persistent fault codes that return immediately after reset point to an active hardware fault — do not loop the reset more than twice; lock out power and run the diagnostic flow for that specific code, or call Hobart-authorized service.

Where can I find the Hobart AM16 dishwasher manual chart of error codes?

The full Hobart AM16 error-code chart is in the AM16 Customer Support Manual (Hobart document F41339, 09/25 revision) — not the operator manual. The Customer Support Manual is distributed to authorized Hobart dealers and service partners; a redacted public copy is also hosted on WebstaurantStore at the AM16 series dishwashers customer support manual PDF link. The chart maps every E-prefixed code (tank-fill, drain, temperature, sanitizer concentration), every F-prefixed fuse callout (F1 relay-board chemical-pump fuse, F3/F4 control-board main fuses), and every chemical-low alert (074–079 series) to the affected component, the recommended diagnostic step, and the wiring-diagram reference. AskWhiz on WhatsApp surfaces the same chart contextually — type the model and the code and you get the chart row for your specific machine without paging through a 200-plus page PDF.

What is an example of a Hobart error code and how does AskWhiz help diagnose it?

Example: a Hobart AM16 displays "F1" and the chemical pumps stop dosing detergent. Without AskWhiz, the technician faces a 200-plus page Customer Support Manual, a wiring diagram fold-out, and a service-menu navigation that varies by firmware revision. With AskWhiz on WhatsApp: send "hobart am16 f1" and you get the chart row (F1 = relay-board fuse for chemical-pump output circuit), the most-common causes ranked by frequency (loose pump connector, corroded terminal, failed pump motor, degraded PS1 power supply), the diagnostic order (lock-out, ohm fuse, inspect connectors, check 24 VDC, isolate pump motors), and the call-the-pro threshold (repeat F1 failures after isolation = relay board or PS1). The same flow works for the most-searched codes — E4 fill, F3 main fuse, PUMPDRN stuck — across AM-15, AM16, AM16VL, and CLeN conveyor models.

Are Hobart mixer and slicer fault codes different from dishwasher codes?

Yes — different product lines, different control architectures, different code conventions. Hobart commercial mixers (Legacy HL series, A-200 bench mixers) use mechanical safety interlocks and limit switches without digital display codes; faults present as no-start or no-speed-change conditions traced via the wiring diagram and the multi-speed gearbox. Hobart slicers (HS-series automatic, EDGE series manual) similarly rely on interlock switches at the carriage and gauge plate — the machine simply will not start with an interlock open. The E/F-prefixed digital code system covered above is specific to the dishwasher product family (AM-series, CLeN conveyor, FT1000 flight-type), where digital controllers manage tank fill, sanitizer concentration, and chemical dispensing. If the GSC query landed on this hub for a mixer or slicer fault, switch to the Hobart Service Parts Online (SPO) portal or the dealer technical hotline — the AskWhiz hub focuses on the dishwasher line where digital code lookup adds the most value.

When should I call Hobart-authorized service instead of fixing it myself?

DIY in-house: clearing a stuck PUMPDRN by pulling the drain trap and removing food debris; resetting the booster heater thermal cutout after the water cools; degreasing the fill-probe hose to clear E4 nuisance trips; reseating loose chemical-pump connectors after F1 once power is locked out; running a manual prime cycle from the Manager Menu. Call Hobart Service for: repeat F1 or F3 fuse failures after one replacement (a downstream component is shorted); transformer T1 absent output; control-board or relay-board-level diagnostics; any work involving the high-voltage element side of the booster heater (single-phase 208/240 V or three-phase 480 V circuits); persistent E-codes after the documented diagnostic flow; and any fault on a dishwasher still under Hobart factory warranty — unauthorized repairs can void coverage and expose the operator to insurance issues.

Quick Answer

Hobart commercial dishwashers (AM-15, AM16, AM16VL ventless, CLeN / CL44eN conveyor) display F-prefixed codes for blown control-board fuses (F1 chemical-pump circuit, F3/F4 main 120 VAC supply), E-prefixed codes for tank-fill, drain, and temperature faults, and PUMPDRN as the normal pump-drain status. Hobart also makes mixers and slicers, but the GSC search intent on "hobart fault codes" is dishwasher-driven.

commercial kitchen

Hobart Troubleshooting Assistant

Get instant AI-powered help for Hobart fault codes and equipment issues via WhatsApp. Our assistant is trained on official manufacturer documentation — available 24/7 for field technicians.

By Nichita Herput

Co-founder & CEO · Reviewed May 2026

What error codes does Hobart display?

120 VAC fuse on the AM16 control board has opened — display goes dark and machine stops; verify line voltage, lock out, ohm F3 and F4, check transformer T1 output, and inspect harnesses for shorts before fitting an identical-rated replacement.

Companion 120 VAC fuse on the AM16 control board (paired with F3); same diagnostic flow applies — a single overcurrent event often pops both, so always test and replace the pair together.

24 VDC fuse on the relay board protecting the chemical-pump output — detergent, rinse aid, and sanitizer all stop dosing; reseat pump connectors, ohm each pump motor, and verify PS1 24 VDC before re-fusing.

Tank-fill timeout or low-water alert — controller never saw the fill probe satisfied within the allowed window; check inlet solenoid strainer, fill float/pressure switch hose for blockage, and confirm the drain ball is fully closed.

Wash-tank temperature out of range — either heat-up failure (failed contactor, failed element, tripped thermal cutout) or temperature probe out of spec; ohm the probe and clamp-meter the heater on a heat call.

Sanitizer or rinse-temperature fault — typically the booster heater is not reaching the 180 °F final-rinse setpoint; check booster element amp draw, thermostat, and incoming water-supply temperature.

Tank fill or water-level fault on AM16 ventless and AM-series machines — confirm 20–90 psi dynamic supply pressure, inspect the inlet solenoid strainer and fill-probe hose, and verify the drain ball seats fully.

Wash-pump or drain-pump current fault — the pump motor is drawing out of range (jammed impeller, debris in housing, failed run capacitor, or shorted winding); lock out and inspect the impeller before clamp-metering the motor.

PUMPDRN

Drain-pump status (normal at end of cycle); becomes a fault when stuck on — clear drain trap, inspect drain ball and solenoid, verify the float switch reads dry when the tank empties.

074

Detergent low alert — the chemical-low input on the relay board reports an empty detergent container; refill or replace the bulk container, then reset the alert per the Manager Menu chemical sub-page.

Common questions about Hobart equipment

What other commercial kitchen brands does AskWhiz cover?

AskWhiz also covers troubleshooting for these manufacturers in the same industry:

Accutemp Alto-Shaam Beverage-Air Blodgett Brema Ice Makers Bunn Cleveland Range Continental Refrigerator Convotherm Cornelius Delfield Electrolux Professional