LX40H

Overview

The Hobart LX40H is a fully automatic, front-loading dishwasher in Hobart’s LX Series. It washes with a fresh-water rinse and has a built-in booster heater. The manual identifies it as model LX40H, publication model number ML-104356. Its standard equipment includes electronic controls, a pumped drain, a fill hose, a drain hose and two racks measuring 20" x 20". The LX Series machines shut down automatically four hours after their last use.

The LX40H is intended for commercial warewashing. Its fresh-water rinse and booster heater make it important to verify the site’s water supply and temperature before installation. The manual gives the usual incoming-water minimum as 140°F; it also notes that the LX40H’s standard heavy cycle can provide a 70°F temperature rise, allowing an incoming-water temperature of 110°F.

Key Features

• Fresh-water rinse: The LX40H uses fresh water for the rinse.
• Built-in booster heater: The booster heats rinse water; the manual describes a typical rise from 140°F incoming water to 180°F.
• Heavy-cycle temperature rise: The LX40H’s standard heavy cycle can provide a 70°F rise, allowing an incoming-water temperature of 110°F.
• Rack format: Standard equipment includes two 20" x 20" racks.
• Pumped drain: A pumped drain and drain hose are included as standard equipment.
• Automatic idle shutdown: The machine shuts down four hours after its last use.

Specifications

• Model: Hobart LX40H.
• Manual model number: ML-104356.
• Machine type: Fully automatic, front-loading dishwasher.
• Motor: 3/4 horsepower electric motor, stated for the LX Series.
• Racks: Two standard racks, each 20" x 20".
• Controls: Electronic controls.
• Drain: Pumped drain; a drain hose is included.
• Rinse: Fresh-water rinse.
• Booster heater: Built in.
• Incoming water temperature: 140°F minimum under the standard LX40H water-supply requirement. The manual states that the LX40H standard heavy cycle can provide a 70°F temperature rise, allowing 110°F incoming water.
• Typical booster temperature: The manual describes 140°F incoming water heated to 180°F.
• Water use: 1.2 gallons per rack for LX40 models; 2.2 gallons per rack for the extended rinse cycle, available on LX40 models in the heavy wash cycle only.
• Wash setpoint: H models have a programmable wash setpoint range of 160°F–170°F; the recommended setting is 165°F.
• Booster setpoint: Programmable from 180°F–199°F; the recommended setting is 190°F.
• Heavy wash time: The recommended LX40H setting is 156 seconds; the programmable range is 100–200 seconds.
• Heavy rinse time: Normal rinse is 10 seconds; extended rinse is 20 seconds.
• Idle shutdown setting: Programmable from 1–6 hours; the recommended setting is 4 hours.
• Water pressure: Flowing pressure requirement is 15–25 psig.
• Recommended water hardness: 4–6 grains per gallon.
• Chlorides: Must not exceed 50 parts per million.
• Drain capacity: The drain must have a minimum flow capacity of 10 gallons per minute.
• Drain connection: The supplied drain hose has a 3/4" pipe connection adapter.
• Water piping: Minimum 1/2" copper piping outside diameter; 3/4" is recommended.
• Water connection: The installation instructions specify a 3/4" male garden hose fitting.
• Automatic shutdown: Four hours after last use as supplied in the LX Series description.

Installation & Requirements

Check the machine for shipping damage after unpacking and contact the carrier within 15 days of delivery if damage is found. Before installation, verify that the electrical supply agrees with the machine data plate. The manual requires electrical and grounding connections to comply with applicable electrical codes; it does not provide an LX40H voltage or amperage figure in the supplied information.

Position the machine and level it before making connections. Use a carpenter’s level diagonally on the rack tracks, adjusting the feet until the machine is level front-to-back and side-to-side. The manual notes that steam may escape from the door during normal operation. It identifies wood, laminates and veneers as unsuitable for areas exposed to dishwasher steam and detergents, and recommends stainless steel or other moisture-resistant shields for adjacent surfaces at the sides and top.

For the water supply, the LX40H requires 140°F minimum incoming water and 15–25 psig flowing pressure under the standard requirement. The manual also explains that the LX40H’s standard heavy cycle can provide a 70°F rise and allow 110°F incoming water. If flowing pressure exceeds 25 psig, install a pressure-reducing valve with a relief bypass; pressure below 15 psig may cause improper operation. A manual shutoff valve should be installed upstream of the fill hose to allow servicing. A line strainer is recommended between the shutoff valve and the machine. A water hammer arrestor meeting ASSE-1010 or equivalent is also recommended in the common water supply line at the service connection.

Use water in the recommended hardness range of 4–6 grains per gallon. The manual cautions that lower hardness can promote corrosion and higher hardness can cause excessive lime scale. Water hardness above 6 grains per gallon should be treated; water below 4 grains per gallon also requires treatment to reduce potential corrosion. Sediment, silica, chlorides and other dissolved solids may call for particulate filtration or reverse osmosis treatment. The manual recommends contacting a local Hobart Service Office for specific water-treatment recommendations.

Before connecting the dishwasher, the plumber must thoroughly flush the water lines to remove pipe chips, joint compound, solder and other debris that could lodge in plumbing components. Use at least 1/2" copper piping outside diameter, with 3/4" recommended. The drain hose must not be kinked, and its drain connection must have a minimum flow capacity of 10 gallons per minute. Plumbing connections must comply with applicable sanitary, safety and plumbing codes.

Operation

Before first use, clean the machine as directed in the manual. Make sure the coarse and fine strainers are in place and free of debris, and check that the wash arms and rinse arms can turn freely. The LX40H has electronic controls. Its LX40H/LX40C programmable settings include wash and booster temperature setpoints, temperature display mode, detergent and rinse-agent settings, idle shutdown time, cycle selection, default cycle, delime counter preset, chemical-pump prime times and heavy-cycle wash and rinse times. The recommended H-model wash setpoint is 165°F, and the recommended booster setpoint is 190°F.

The recommended heavy wash time is 156 seconds, within a programmable range of 100–200 seconds. The heavy rinse can be set to a 10-second normal rinse or a 20-second extended rinse. The extended rinse is available on LX40 models in the heavy wash cycle only; the manual lists water use of 2.2 gallons per rack for that option, compared with 1.2 gallons per rack for LX40 models. The LX Series automatic shutdown occurs four hours after last use, and the LX40H manager setting can be programmed from 1–6 hours.

For the LX40H, follow the water-temperature requirement that applies to the selected cycle and the installation conditions. The manual gives 140°F as the usual minimum incoming temperature for LX40H and describes heating that water to 180°F in the booster. It specifically identifies the standard heavy cycle as providing a 70°F rise, which allows 110°F incoming water. Do not assume that this lower incoming-water figure applies to every cycle.

Cleaning & Maintenance

Clean the machine at least once each working day. At the end of the day, press OFF; the machine drains. When the display is no longer lit, open the door and remove debris from the bottom of the tank. Do not allow food soil to accumulate there.

For the LX40H, remove the lower rinse arm by unscrewing its knurled knob, then pull the lower wash arm off its shaft. Remove the upper rinse and wash arms in the same manner. Remove the coarse and fine strainers, and thoroughly clean the arms and strainers in a sink. With a damp cloth, wipe the interior, the water-level probes and the probe under the fine strainer. Do not use steel wool. Wipe the exterior and the lip at the bottom of the door. For remaining soil, use a mild cleanser formulated for stainless steel and a soft cloth or brush.

Replace the coarse and fine strainers. Reinstall the lower wash arm by pushing it down onto the shaft, then place the lower rinse arm on the shaft and tighten the knurled knob. Spin the arms to make sure they turn freely. Repeat for the upper wash and rinse arms. Clean the control keypad and display with a soft damp cloth or sponge and mild cleanser; do not use abrasive or harsh cleaners or scouring pads. Leave the door ajar overnight so the interior can air out and dry.

Use only products formulated to be safe on stainless steel. Do not use residential-dishwasher detergent, allow food soil to collect in the tank, exceed chemical manufacturers’ recommended concentrations, or allow foreign objects—especially metallic contaminants—to enter the machine. The manual recommends following the chemical professional’s prescribed deliming schedule. Its deliming guidance warns not to leave deliming agent in the machine longer than its manufacturer recommends. The pump motor has permanently sealed bearings and requires no lubrication. Failure to follow the use, care and maintenance instructions may void the Hobart warewasher warranty.

Troubleshooting

• No operation and no display: Check that the machine is ON, inspect the power-supply fuse or circuit breaker, and check that the cord is plugged in on corded models.
• No operation with a display: If the display shows “dr,” “oP” or “door open,” open and close the door. If the problem persists, contact a local Hobart Service Office. The troubleshooting table also refers operators to the “Machine won’t fill” checks.
• Dishes are not clean: Clogged strainers can restrict water supply to the pump; clean them as directed. Check for obstructions in the wash arms and make sure the arms turn. On LX30 and LX40 models, check that the rinse arms also spin. The detergent dispenser may be clogged. Scrape dishes before washing.
• Low temperature readings: Check that incoming water meets the recommended temperature. Rapid cycle use combined with low incoming-water temperature can leave the hot-water supply unable to meet demand. Heavy ware loads can cool wash water, so do not overload racks. The manual says to raise the booster or sump heater setting on the LX40H if it is set too low.
• Machine will not fill or will not fill high enough: Low water pressure is a possible cause. Check for a clogged hose strainer and confirm site pressure meets the minimum flowing-pressure requirement. Clean the water-level probes as directed. Check whether the main water-supply valves are working. A drain valve left open can also be involved; the manual’s LX40 display messages include “DR1 PRBLM,” “FILL1 PRBLM,” “FILL2 PRBLM” and “FILL3 PRBLM.”
• Possible drain-valve obstruction: The manual instructs operators to turn the machine OFF to drain it, turn it ON, and repeat twice to help clear a drain-valve obstruction. Wait for READY mode and press WASH. Then slowly open the door and note the water level; close it, wait 30 seconds, and check the level again. If the level has changed, repeat the OFF-ON procedure. If the problem persists, contact a local Hobart Service Office.

Applications

The LX40H is suited to commercial kitchens that need automatic rack-based dishwashing with a fresh-water rinse and a built-in booster heater. Its 20" x 20" racks, pumped drain and programmable heavy-cycle wash and rinse settings support routine warewashing in foodservice operations. Confirm incoming-water temperature, flowing pressure, water quality and drain capacity against the manual’s requirements before putting the machine into service.