If a few minutes after turning the dryer on, a burning smell is noticed, it is usually due to the lint filter being damaged, full, or not cleaned regularly and now the lint is touching the drying element.
It is recommended that you clean the lint filter after every use to avoid build up and to replace the lint filter once a year. It is so important in stopping the lint from gathering around the dryer element.
Regular cleaning of your dryer filter ensures your clothes are lint free and reduces the fire hazard which can be caused by built up lint.
If the dryer has been left with the filter damaged or not cleaned, it is strongly recommended that you contact a repairer to come and dismantle the dryer for cleaning.