MCO-GD-20-S

Overview

The Garland MCO-GD-20-S is a full-size, deep-depth, double-deck gas convection oven in Garland’s Master Series. Its two cooking cavities provide space for simultaneous or sequential batches, making the unit suitable for commercial kitchens that bake, roast or cook multiple pans during service. The model is listed as a natural-gas oven; Garland’s manual says to specify the gas type when ordering and to connect the appliance only to the fuel type shown on its rating plate.

The oven has Master 200 solid-state controls with a one-hour timer, electric ignition and two-speed fans. The product information identifies stainless steel for the front, sides and top, and porcelain for the cooking cavity.

Key Features

• Double-deck format: Two deep-depth cooking cavities provide separate oven spaces within one full-size unit.
• Two-speed fans: The two-speed fan system circulates heat through the cooking cavity.
• Master 200 controls: Solid-state controls and a one-hour timer provide temperature and timed-cooking control.
• Rack flexibility: Chrome-plated oven racks sit on 13-position rack guides.
• Commercial construction: The front, sides and top are stainless steel; the cavity is porcelain.
• Ignition and doors: Product information specifies electric ignition and dependent 60/40 doors with windows.

Specifications

• Manufacturer: Garland
• Model: MCO-GD-20-S
• Series: Master Series
• Equipment type: Gas convection oven
• Configuration: Full-size, deep-depth, double-deck
• Fuel: Natural gas listing; manual says to specify gas type and match the fuel to the unit’s rating plate.
• Total input: 120,000 BTU/hr for a double-deck model.
• Interior dimensions: 29" W x 24" H x 28" D per cavity.
• Exterior dimensions: 38" W x 70.5" H x 44.5" D.
• Shipping weight: 1,090 lb for the deep-depth double-deck model in the installation and operation manual.
• Racks: Six chrome-plated oven racks on 13-position rack guides are specified in the product description.
• Cavity height: 24".
• Controls: Master 200 solid-state controls with electromechanical timer.
• Fan: Two-speed.
• Ignition: Electric.
• Doors: Dependent 60/40 doors with windows.
• Exterior and cavity materials: Stainless steel front, sides and top; porcelain cavity.
• Legs: 6-1/2" legs are specified in the product description.
• Gas inlet: 1" NPT at the rear for double-deck models.
• Electrical ratings: The manual lists 120V/1-phase at 9.8A per deck or 240V/1-phase at 5.2A per deck. It specifies two electrical connections for a double-deck model.
• Plug and circuit information: A 6-foot line cord with NEMA 5-15P plug is provided for each 120V deck. Garland recommends a separate 15A circuit for each 120V unit.

Installation & Requirements

Clearances and access

For double-deck models, the installation and operation manual specifies minimum clearances beside combustible and non-combustible walls of 1" on the left side, 2" on the control side and 3" at the rear. Near high-heat-producing equipment, the stated minimums are 1" on the left, 6" on the control side and 3" at the rear. The manual recommends 12" of control-side clearance for service access. Entry clearance is 47" when crated and 32-1/2" when uncrated.

Gas connection

The rear gas inlet for double-deck models is 1" NPT. The manual warns that undersized supply piping can restrict gas and affect performance. If other appliances share the line, it must carry the combined gas load without more than a 1/2" water-column pressure drop at each appliance manifold at full rate. For two stacked ovens, the manual gives 1" as the minimum recommended size for a single supply line.

The manual lists recommended supply pressures of 7" WC for natural gas and 11" WC for propane, each ±5%. It states maximum supply pressures of 13.8" WC for natural gas and 15" WC for propane. The operating-pressure table lists 4" WC for natural gas and 10" WC for propane. Confirm the oven’s fuel type from its rating plate; the manual says a unit marked NAT must be connected to natural gas and a unit marked PRO to propane. Installation must follow applicable local codes or the codes identified in the manual.

Electrical connection

Each oven requires a 15A electrical service. The manual lists 115V, 3/4 HP, two-speed motors for 120V units and 200–240V, 3/4 HP, two-speed motors for 240V units. Each 120V deck has a supplied 6-foot cord with a NEMA 5-15P plug, and Garland recommends a separate 15A circuit for each 120V unit. The appliance must be grounded in accordance with applicable local requirements; the manual cautions not to cut or remove the grounding prong.

Ventilation and air supply

The manual says proper ventilation is important and identifies two methods for venting: a canopy-style hood or direct venting. It also warns that objects placed in front of the oven can obstruct airflow, and that objects on the rear of the top can obstruct flue-product venting. Commercial cooking equipment requires adequate ventilation; the manual refers to NFPA 96 for additional information.

Operation

The Master 200 control system includes temperature and timer functions. The product description specifies a one-hour timer. The manual’s control section identifies start-up, fan speed, lights, cool-down, temperature and timer functions. The oven’s two-speed fan circulates air through the cavity; use the fan-speed setting appropriate to the cooking task.

For a new oven, the manual directs operators to run it for one hour at 375°F before normal cooking. It also states that no attempt should be made to operate the oven during a power failure. Gas burners and pilots require sufficient air, so do not obstruct the front airflow or the rear flue venting.

Cleaning & Maintenance

Disconnect the line cord from the power supply before cleaning or servicing. During the new-oven break-in procedure, allow the oven to cool after its one-hour run at 375°F, then wipe the interior and racks with a clean, damp cloth. The manual advises establishing a regular schedule for exterior cleaning and wiping spills off immediately.

If aluminum foil is routinely used to wrap food or cooking vessels, the manual specifies fan-area maintenance: turn the power switch off, remove the racks and rack guides, remove and clean the air baffle, and check the blower wheel and baffle for foil or food deposits. Clean the blower-wheel fins, taking care because their edges may be sharp, then reinstall the baffle, rack guides and racks.

The manual describes the motor as maintenance-free, with self-lubricating sealed ball bearings. It cools internally through air entering at the rear of the motor case, so the specified installation clearances matter for motor airflow.

Troubleshooting

Baking and roasting results

• Cakes are dark on the sides but underdone in the centre: Lower the oven temperature.
• Cake edges are too brown: Reduce the number of pans or lower the temperature.
• Cakes have a light outer colour: Raise the temperature.
• A cake settles slightly in the centre: Bake longer or raise the temperature slightly; avoid opening the doors too often or for long periods.
• Cakes ripple: The manual identifies overloaded pans or batter that is too thin as possible causes.
• Cakes are too coarse: Lower the oven temperature.
• Pies have uneven colour: Reduce the number of pies per rack or eliminate bake pans.
• Cupcakes crack on top: Lower the oven temperature.
• Meat is browned but underdone in the centre: Lower the temperature and roast longer.
• Meat is overdone and browned: Reduce the cooking time.
• Meat develops a hard crust: Lower the temperature or place a pan of water in the oven.
• Rolls have uneven colour: Reduce the number or size of pans.

Ignition sequence

The service manual describes the gas ignition sequence as a call for heat, pilot-valve operation and spark, followed by flame detection and opening of the main gas valve. If the pilot does not ignite during the trial period, the described control enters a 90-second safety lockout. The service manual says the control can be reset by setting the thermostat or controller below room temperature or to OFF, or by switching system power off. Gas-system diagnosis and repair should be handled by qualified service personnel.

Applications

The double-deck layout and rack guides suit commercial kitchens handling batches of baked goods, roasted meats, rolls, pies and other pan-cooked items. Two cavities allow separate cooking loads or products to be handled in the same oven footprint, while the 13-position rack guides offer flexibility in rack placement.