Oven cleaning checklist
How to clean an oven without ruining it: identify the cleaning type first, choose the method second. Pyrolytic, catalytic and enamel ovens need different steps and have different bans.

[ ] Identify the cleaning type from the manual
    Pyrolytic, catalytic, hydrolytic or plain enamel — everything else follows from this. The manual also says what must not stay inside and what must not be used.
[ ] Let it cool down and disconnect the power
    Working in a hot cavity is dangerous and cleaners evaporate instantly on hot surfaces. Cutting the power is essential before touching the lamp or fan.
[ ] Ventilate the kitchen and put on gloves
    Degreasers are alkaline and irritate skin and airways. Open a window or switch on the extractor before applying, not after.
[ ] Take out trays, shelves and runners
    Empty the cavity completely. The manual says what may go in the dishwasher and what may not: some runners and coatings are damaged by it.
[ ] Soak the trays and shelves in hot water
    Cover them with hot water and degreaser at the start. While you work on the cavity, the baked-on grease softens and comes off without abrasives.
[ ] Remove crumbs and debris from the floor of the oven
    Collect dry debris before any washing, or it smears around the walls together with the cleaner.
[ ] Soften the residues with steam
    Put a container of water inside and heat it as the manual describes: the steam softens the deposits. This is safe for most ovens, but check whether yours has a dedicated programme.
[ ] Clean the enamel with a soft sponge and an approved product
    Give the product its stated contact time and lift the residue without pressure. Wire wool and powders leave scratches where food burns on even faster.
[ ] Care for catalytic liners the way the manual says
    This coating must not be scrubbed or treated with harsh cleaners: it breaks down grease itself when heated. Usually only a soft damp cloth and a heating cycle are allowed.
[ ] Run the pyrolytic cycle as the manual says
    Remove everything the manual says to remove, including the runners if required. Ventilate the kitchen and do not leave the cycle unattended.
[ ] Once cool, wipe out the ash with a damp cloth
    A grey powder is left on the floor of the oven — all that remains of the residue. Wipe it out only once the cavity is completely cool.
[ ] Clean the door glass on both sides
    Work gently: scratches in glass never come out. Take the door apart only in the way, and in the cases, your model's manual describes.
[ ] Wipe the door seal with a damp cloth
    Do not brush it or soak it in cleaner: a damaged seal lets heat out and the oven starts cooking unevenly.
[ ] Keep clear of the fan, lamp and heating elements
    Never pour water or cleaner over them. Remove dust and splashes nearby with a barely damp cloth and the power off.
[ ] Rinse all product residue away with clean water
    Product left behind burns off at the next heat-up and gives a smell and a taste. Go over the cavity several times and dry it.
[ ] Heat the empty oven and ventilate
    A short heat-up as the manual describes removes any remaining smell before food goes in. Keep the kitchen ventilated while it runs.
[ ] Put the dry trays and shelves back
    Damp accessories in a warm cavity cause rust marks and smells. Let them dry completely.

Checklist from Unload: https://unloads.me/c/oven-cleaning