Fixing Carpet “ripples”

You may get away with out emptying the room. But given the age of the carpet and how long the ripples have been there. They may not come out

Would recommend empty room release carpets from all walls and try stretching again may take some ripples out but age of carpet cannot guarantee

Given the age backing of the carpet may have come away from the actual carpet, so ripples will not disappear, but as the others say, empty the room, release carpet from grippers, restretch the carpets..

Ide recommend clearing all objects from the room area,as I would release carpet off of grippers on the entire room & then double up on new grippers & try & re-stretch your carpet back onto grippers & tuck down..... “failing this as your carpet is 20 odd years old.. we could try another option which would be to release carpet off of grippers... fold carpet in half.. glue out folded area.. then the same the other side.. re-stretch it all rub it down & fit it..”

Ideally the room needs to be emptied, the Carpet may just need to be Re-Stretched onto the Grippers to pull the creases out, having the room empty will mean that nothing is holding the carpet down and it's free to move and stretch. The Carpet will need to be pulled up at least at all the edges, if not more. Condition of the Grippers will need to be assessed. But with the age of the Carpet there may not be anymore Stretch in it due to it's age.

After 20 years of service, I think you've probably had as much wear as you are going to get from your carpet and is really time to bite the bullet and buy a new one. Paying someone to call round and try to make good is just throwing money down the drain in my humble opinion.