My rabbits donot drink water .plz help?

1 month before i have bought two rabbit of 4 -5 months.. but they are not drinking water since i have purchase them i have tried almost everything wet leafs , ice cubes etc but they are not drinking water, there urination is fine but i am worried that they will get dehydration though they are normal since 1 month from the time i have bought.i think the shopkeeper didn't gave them water so have not develop the habit of drinking . Since summers are going to start i am worried about there water intake.