Commercial Dishwasher Repair

Standing water in the wash tank after the cycle is the most common call we get for commercial dishwashers. A clogged drain pump filter blocked by food debris is the first thing to check before calling for service: commercial units accumulate debris significantly faster than residential machines. A failed drain pump motor that hums but moves no water is the mechanical cause when the filter is clear.

A blocked drain hose or a jammed drain valve are secondary causes. Write down any error codes on the display before calling for service: fault codes cut diagnostic time significantly on modern commercial units.

A commercial dishwasher that fails to reach the required wash or rinse temperature will fail a health inspection. On high-temp units, a failed booster heater is almost always the cause when rinse temperature falls short: the booster heater raises incoming water temperature to the 180°F required for chemical-free sanitizing. A failed thermostat or temperature sensor sending incorrect readings to the control board produces the same symptom.

On low-temp units, a failed chemical sanitizer dispenser that stops injecting sanitizer into the final rinse is the critical failure: the machine appears to run normally but dishes are not sanitized. Book online for a fast response.

When dishes come out still dirty after a full cycle, the cause is almost always water pressure or spray coverage. A clogged wash arm or rinse arm with blocked nozzles is the most frequent cause: remove each arm and clear the holes before calling for service. A failed wash pump that doesn’t generate sufficient pressure is the mechanical cause when spray arms are clear.

A water inlet valve that doesn’t fill the tank to the correct level produces the same result. Check that the correct detergent concentration is being used: under-dosing produces poor results that look like a mechanical fault.

Water on the kitchen floor during or after the wash cycle creates a slip hazard and a health inspection concern. A worn door gasket is the most common source on door-type and undercounter machines: the gasket compresses over time and stops sealing the door perimeter completely. A loose or cracked drain hose connection at the pump is the second cause.

Water pooling under the unit only after the drain cycle points to the drain connection. On conveyor machines, overflow from a tank that isn’t draining completely between cycles pools on the floor and is often misidentified as a leak.

Commercial dishwashers sanitize through one of two methods. High-temp systems use a booster heater to raise the final rinse water to at least 180°F: no chemical sanitizer is required. Low-temp systems use chemical sanitizers injected into the final rinse at ambient water temperature: the chemical sanitizer dispenser must work correctly or dishes are not properly sanitized.

A machine that looks like it’s running normally but isn’t sanitizing will pass a visual check and still fail a health department test. We confirm both temperature and chemical concentration on every commercial dishwasher call.

Hobart is the commercial dishwasher brand our technicians see most often on service calls. The LX undercounter and AM door-type series are workhorses in small and mid-size Denver restaurants. Their most common failures are a wash pump that loses pressure over high-cycle use and a booster heater that stops maintaining sanitizing temperature. Wash arms also clog with food debris and mineral scale (water hardness varies by utility across Denver Metro).

On the larger CL conveyor and FT flight-type machines, door gasket wear and control board errors are the most common calls. We source Hobart parts through national supplier networks and manufacturer contracts. Book online for fast response.