Why are my units burning at either side of the oven or cooker?
If you are getting burning or scorching at either side of the oven on the units it is normally a problem with the door or door seal.
If your cooker is a few years old the door seals maybe worn or perished causing the door not to seal correctly. This will cause heat to escape and it can result in damage on your units.
You should also check your door hinges, these have tendency to go on fold down doors - there is always a temptation to rest plates and pots on the open door. These hinges will not support this additional weight and over time it will warp the springs in the hinges, causing the door not to seal completely. Additionally on side opening doors, the hinges can get bent out of shape, preventing the door from completing a clean seal around the oven.
As well as the door hinges, the door latch needs to be checked. With age, the door latch will wear allowing small movement or 'play' in the door when it is in the closed position. If you are able to rattle your door in the closed position then your latch and striker need replacing and heat will be escaping from the oven.
All of these problems can contribute to your units burning at either side and should be addressed by sourcing the appropriate spares.
If you have a newer appliance that has not been installed too long (months, not years) it will almost certainly be due to either a poor installation with inadequate ventilation or not enough space allowed between the oven front and the adjacent doors. In new appliances is very unlikely for this to be caused by a fault with the appliance, other than physical damage causing the door to not seal correctly.