Yes, a wall oven needs wiring to operate.
Depends on the load of the oven. More than likely it will require AWG #6 but you need to read the electrical requirements for that particular oven.
A wall oven is an oven that is installed inside the kitchen wall and does not extend far into the kitchen, as opposed to an oven that is separate from the rest of the kitchen and not affixed to the wall.
This is just a guess, but it sounds like the person fitting the oven does not want to have a new 240 Volt circuit installed to supply the oven and plans to use an existing 120 Volt wall outlet using a 120-to-240 Volt step-up transformer. To conform to the latest Wiring Codes, a wall oven usually has to have its own dedicated circuit with correctly sized breakers, wiring and outlet. The circuit should be designed to supply whatever voltage and current the wall oven requires without using any separate transformer. Are you are having the wall oven installed by a licensed electrician or by a kitchen fitter? If you are not sure if the person who is talking about using a transformer is actually a licensed electrician who is following the Wiring Codes for your locality (Town/State) then the best advice anyone should give you is to refuse to have any electrical work done for your wall oven until you have had a second opinion from an independent licensed electrician or electrical engineer.
The steps involved in wall oven installation include measuring the space, preparing the area, connecting the electrical or gas supply, mounting the oven into the wall, and testing the oven to ensure it is working properly.
There are ovens as small as 24 inches or 27 inches. Those seem to be the smallest wall ovens. They are produced by Kenmore, Frigidaire, or General Electric.
The "FO" error code on a GE Profile double wall oven typically indicates a fault in the oven's control board or a problem with the temperature sensor. This might be caused by wiring issues, a malfunctioning sensor, or an internal fault within the oven's electronics. To resolve the issue, it’s advisable to reset the oven by turning off the power for a few minutes, and if the error persists, contacting a qualified technician for further diagnosis is recommended.
A contractor drilled into the wall by accident. Should the contractor replace the wiring in the wall in order to pass inspection.
GE 24-inch Gas Wall Oven - 127lbsGE 27-inch Single Convection Wall Oven - 128lbsGE 30-inch Single/Double Convection Wall Oven - 188lbsGE 30-inch Double Convection Wall Oven - 249 lbsI have also heard of double ovens weighing in at up to 300lbs.Then there are commercial ovens which are obviously huge.
GE 24-inch Gas Wall Oven - 127lbsGE 27-inch Single Convection Wall Oven - 128lbsGE 30-inch Single/Double Convection Wall Oven - 188lbsGE 30-inch Double Convection Wall Oven - 249 lbsI have also heard of double ovens weighing in at up to 300lbs.Then there are commercial ovens which are obviously huge.
I assume you mean "built in" not "in built." A built in oven is an oven that is not mobile, and it is built in to the wall of the kitchen.
try www.consumersearch.com/wall-oven-reviews
An electrical short in the wiring, or a defect in the oven itself. Have it checked out by a qualified technician.