I have a Gwyneth Toilet that is about 5 years old. This week it decided to act up and wont stop running. When the tank gets full, the water keep coming in.

Under t he lid are codes THU253s, THU277s, and THU299s.

I have tried adjusting the water level, but it doesn't make any differance.

Can anybody tell me what parts I need?

Thanks!
Ron