Why are some of my pans now curved on the bottom?

[ScotHill]

Some of them worse than others, induction hob, probably been used for 5-6 years now.

Is there any way of flattening them out again?

[Drive it fix it repeat]

Heat distortion, and not easily. Could try laying them face down and trying to knock the centre back down level but even if it works I would expect it to happen again quickly.

[Baldchap]

Do you rinse them out with cold water before they have cooled down?

[ScotHill]

Baldchap said:

Do you rinse them out with cold water before they have cooled down?

We're conscious not to, could have happened though, but would never have been from roasting hot. The induction hob can put a lot of heat straight through the pan, don't know if it's a known issue with those jobs? Could just be cheap pans too.

[21TonyK]

If its not thick enough any pan will warp eventually. Time to invest.

[Teddy Lop]

ScotHill said:

We're conscious not to, could have happened though, but would never have been from roasting hot. The induction hob can put a lot of heat straight through the pan, don't know if it's a known issue with those jobs? Could just be cheap pans too.

are they rated induction compatible or do they just "seem to work"

If the latter they could have more aluminium/copper layers in the base as well as steel which isn't ideally what you want for induction and be causing it- see how a bimetallic strip works eg inside a thermostat.