MCO-GS-20

Overview

The Garland MCO-GS-20 is a Master Series, double-deck gas convection oven for commercial kitchens. Its two separate oven compartments let operators cook different items in each deck or use both cavities for larger production runs. Each cavity measures 29 inches wide by 24 inches high by 24 inches deep in this standard-depth model. The oven uses natural gas or propane and has a combined input rating of 120,000 BTU, or 60,000 BTU per cavity.

Convection airflow circulates heat through each cooking cavity. The oven has a two-speed fan with high and low settings, and its temperature range is 150°F to 500°F. Each deck has its own cooking space, racks and controls. The Garland manual covers the MCO-GS-20 among its Master Series full-size gas models; control packages and electrical configurations can vary, so confirm the unit’s data plate and supplied configuration when identifying a particular oven.

Key Features

• Two independent decks: The double-deck format provides two oven cavities, each with 13 rack positions and six chrome-plated oven racks.
• Two-speed convection fan: High and low fan settings support different cooking requirements. Each cavity uses a 3/4 HP fan motor.
• Broad cooking range: The thermostat range is 150°F to 500°F (66°C to 260°C).
• Commercial construction: The specification describes stainless steel front, sides, top and legs. The interiors are porcelain enamel with coved corners.
• Visible cooking: Double-pane thermal windows and interior lighting let staff monitor food without opening the doors.
• Dependent doors: The 60/40 door arrangement uses a full-length positive closure and the patented Safety Door System.
• Gas ignition and safety: The oven uses electronic spark ignition with an automatic pilot system and 100% safety shut-off.
• Control options: The manuals and specification identify Master 200 controls, as well as optional Master 450, 455 and 475 electronic control packages. The 455 adds a core probe to the 450 features; the 475 adds programmable product keys. Verify the control package on the specific unit.

Specifications

• Product type: Double-deck, full-size gas convection oven
• Model: Garland MCO-GS-20
• Fuel: Natural gas or propane; specify gas type when ordering
• Total gas input: 120,000 BTU (35.2 kW equivalent)
• Gas input per cavity: 60,000 BTU (17.6 kW equivalent)
• Oven interior, each cavity: 29 inches wide × 24 inches high × 24 inches deep
• Overall dimensions: 38 inches wide × 41 1/4 inches deep × 70 1/2 inches high
• Shipping weight: 1,030 lb for the standard-depth double-deck model
• Rack configuration: Six racks per cavity; 13-position rack guides per cavity; 12 racks total
• Fan: Two-speed, 3/4 HP fan motor per cavity
• Temperature range: 150°F–500°F (66°C–260°C)
• Gas connection: One 1-inch NPT rear inlet for double-deck models
• Electrical configurations: The manual lists 120 V, single-phase and 240 V, single-phase options. The specification lists 115 V, 60 Hz, single-phase as the standard configuration and specifies the alternate voltage when ordering.
• Electrical draw: The installation and operation manual lists 9.8 A per deck at 120 V or 5.2 A per deck at 240 V. The 120 V version has a 6-foot cord with a NEMA 5-15P plug for each deck.
• Interior and exterior materials: Porcelain-enameled cavity; stainless steel front, sides, top and legs
• Listings stated in the specification: UL, cUL Classified and NSF Listed
• Warranty stated in the specification: One-year limited parts and labour warranty and five-year limited door warranty, excluding the window

Installation & Requirements

Installation must follow applicable local codes and the manual’s instructions. For a double-deck unit, the manual specifies a minimum clearance of 1 inch at the left side, 2 inches at the control side and 3 inches at the rear when installed beside combustible or non-combustible walls. Near high-heat-producing equipment, the stated minimums are 1 inch at the left side, 6 inches at the control side and 3 inches at the rear. The manual also recommends at least 12 inches of control-side clearance for service. It cautions against placing the oven near equipment such as char-broilers or fryers that produce high heat and grease-laden air.

The oven requires adequate ventilation. The manual identifies two methods: a canopy hood or direct venting. Keep the front unobstructed so burners and pilots have sufficient air, and do not place objects on the rear top of the oven where they could obstruct the flue venting system. The manual notes that gas input ratings apply to installations up to 2,000 feet above sea level and says to specify higher-altitude installations.

The double-deck gas inlet is 1-inch NPT at the rear. The manual gives recommended supply pressures of 7 inches water column for natural gas and 11 inches water column for propane, each ±5%; it states maximums of 13.8 inches water column for natural gas and 15 inches water column for propane. It also says the gas supply line must be sized for the combined volume of connected appliances without more than a 1/2-inch water-column pressure drop at the appliance manifold at full rate. The oven’s data plate identifies the gas type: connect a unit marked NAT to natural gas and one marked PRO to propane.

Provide a 15 A electrical service for each oven deck, as stated in the manual. The 120 V version is supplied with a grounded three-prong plug for each deck; the manual says not to remove the grounding prong and recommends a separate 15 A circuit for each 120 V unit. The manual also requires the oven to be level and, for caster-equipped units, specifies an approved gas connector, quick-disconnect device and restraint.

Operation

Operating controls depend on the control package fitted to the oven. The Master 200 control described in the product information has a three-position switch for off, cook or cooldown, a rotary temperature control, high and low fan settings, a timer and an audible signal when the timer cycle ends. Indicator lights communicate operating status. The manual also documents optional Master 450 and 455 electronic controls with cook-and-hold functions; the 455 adds a core probe. The Master 475 control adds programmable product keys and a shelf timer. Check the control panel and its instructions to confirm the functions on the particular MCO-GS-20.

The oven’s automatic ignition sequence uses a pilot and electronic spark ignition. The service information describes a safety lockout if the pilot does not ignite during the ignition trial; resetting procedures depend on the control system. The user manual states that the oven should not be operated during a power failure.

Cleaning & Maintenance

For a new oven, the user manual instructs operators to run it for one hour at 375°F (191°C) before normal cooking. After it cools, wipe the interior, including the racks, with a clean damp cloth. The manual advises establishing a regular exterior-cleaning schedule and wiping spills as soon as they occur. Disconnect the line cord from the power supply before cleaning or servicing.

If aluminium foil is routinely used to wrap food or cooking vessels, the manual calls for preventive cleaning of the fan area: switch the oven 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 says the motor has sealed, self-lubricating ball bearings. It cautions that stopping the motor while the oven is hot can transfer heat from the blower wheel into the motor, potentially shortening motor life.

Troubleshooting

The user manual’s cooking guide offers adjustments for common baking and roasting results. If cakes are dark at the sides but underdone in the centre, lower the oven temperature. If cake edges brown too much, reduce the number of pans or lower the temperature; if cakes have a light outer colour, raise the temperature. A cake that settles slightly in the centre may need more baking time or a slight temperature increase. Avoid opening the doors too often or leaving them open for long periods.

For uneven pie colour, reduce the number of pies per rack or avoid bake pans. If cupcakes crack on top, lower the temperature. For meat that is browned but not done in the centre, lower the temperature and roast longer. If meat is too well done and browned, reduce the cooking time. The manual also recommends limiting moisture when meat is too well done and browned; for a hard crust, reduce the temperature or place a pan of water in the oven. Unevenly coloured rolls may call for fewer or smaller pans. For service issues involving gas, ignition or electrical components, consult the model’s service information and use qualified service personnel.

Applications

The double-deck layout and multiple rack positions suit commercial kitchens producing several trays of baked goods, roasted meats or other oven-cooked menu items during busy service. Separate cavities allow staff to organise cooking by product or batch, while the temperature and two-speed fan settings provide operating choices for different loads. The listed uses are practical examples; follow the recipe and the oven’s operating instructions for each product.