
you will hve to revert back to basics a phrase well used on this website!
treat him as you would a 7 wk old pup and start at the beginning . I train a pup by taking him out side every 20 to 30 minutes use words for toilet I say 'be a good girl' as soon as they go lots of over enthusiastic praise .
After meals before bed and sometimes it pays to get up in the night and let them out. stay with him to toilet so that you know he has been.
If her has been kenneled I would imagine it will take a while for him to grasp that it is unacceptable to pee in the house as he will have been doing just that in his kennel .
You have to train his way of thought continually repeating the same routine will work its a pain but will work if you continue.
Also when a pup is about to toilet they usually sniff the floor ,circle as soon as you see these actions make a sound I say quick, quick, quick this usually stops them until you can guide them outside...then remember lots of praise so he knows he is doing good.
He may take a while to toilet on walks he has a routine he has been doing for 6m ...some dogs wont go outside thier toileting area at hme.
HTH
Roni