i would check you cooktop as-well my electric cooktop gives off some random odors while cooking.
but for your pots i would recommend ‘seasoning’ them. that’s were you put enough table salt in them to cover the base then heat slowly,the salt will draw out anything unseen in the metal and you will notice the salt change colour. then once you are done pour out the salt (get rid of it) then wipe out the pot with oil. this will seal the pan and make it stick less. this should fix your problem

Sounds like your pots have absorbed something – the vinegar and bicarb option sounds good.

I’ve never come across this before but I like the vinegar and bicarb answers.

I like the answer’s! Try bicarb of soda that usually helps with odours. Thanks

Interesting reading the comments!

i don’t know…..maybe try to google this

i have not heard of this before. but could try bicarb of soda was that usually helps with odours.

You have had them a long time sounds like its time to go shopping!

Vinegar definitely helps, be careful when you scrub the base of pot and always use lukewarm water when cleaning the pot.

Do they have copper bottoms and have they started to pull apart? Could be moisture trapped between perhaps.

I had a similar problem and was told to use 1 cup vinegar & 3 cups of water on a low heat for as long as you can. I did mine for 6 hours and have never had a problem since

Was there any moisture on the base of the pots when you put on your cooktop or in oven?? That will make them smell. If you have scrubbed the pots with anything hard you have probably damaged the surface and made tiny grooves.

Boil 1 part vinegar 3 parts water for about 4 hours.

I have no idea. I would try a vinegar soak

Sounds odd, maybe talk to someone in a kitchen wares shop?

No ,but try a vinegar wash ,being a acid it may help .

Could it be at some time the handles on the pots might of gotten burnt? So when the pots heat up the handle that have been damaged at some point start to smell?.