How to Disconnect the Ventilation Pipe From a Built-In Oven

Venting

• Ventilation practices for built-in ovens differ from range hoods and those serving some microwaves. The amount of heat and moisture to be vented, and -- in the case of natural and propane gas-fueled burners -- the presence of combustion gases, means that recirculatory devices are not satisfactory. Built-in ovens are, by definition, enclosed inside a cabinet, where the buildup of heat and combustion gases could be extremely dangerous. They must be vented via ductwork to the exterior of the building.

Disconnection

• The duct, or pipe, that leads to the exterior exhaust is invariably attached to the outlet of the oven’s vent using a special heat-resistant rubber boot that deforms to fit over the typically oblong vent and the usually round duct. The most common size of duct is 6 or 7 inches, and vents usually measure 3 1/4-by-10 inches. The boot is held in place by two hose clamps, one at either end.

  Follow the instructions in the manufacturer’s manual to disconnect the vent pipe. Typically, the process involves first using a flat-bladed screwdriver to loosen the hose clamps -- righty-tighty, lefty-loosey -- until they can be rotated freely around the ends of the rubber boot. Next, grasp one end of the boot and work it backward and forward an inch or two while pulling it away from the oven or the vent pipe, whichever is easier. When the boot comes free, the vent pipe is disconnected from the oven.

Ancillary Components

• Such externally vented systems should have a grease filter within the ducting. If the system does not have a filter, grease will solidify and collect inside the ducts, eventually becoming a fire hazard and restricting the amount of air that can be moved. Cleaning should be carried out regularly by specialist contractors; vent cleaners typically advertise in the “Chimney Sweeps” section of telephone directories, and the contractor should be an expert in disconnecting the duct pipe from the vent. The ductwork can contain a filter, a damper to prevent back drafts and an air-moving device, typically a traditional, bladed rotary fan or a more modern centrifugal unit. These components are typically remote from the oven, so removal of the duct need not disturb them.

Integral Vents

• Most ovens also have a vent at the front that exhausts into the kitchen; this vent is not connected to a pipe. Such integral vents must never be closed, covered or obstructed in any way. The oven is designed to work best with a circulation of air. If the circulation is interrupted, cooking performance will be negatively affected. Further, the air being exhausted can be hot enough to set fire to dishcloths or melt plastic utensils if they are hung directly over the mouth of the vent.