This study will evaluate the safety and efficacy of valsartan plus HCTZ in fixed dose combination in hypertensive patients not responding to treatment with the free combination of Candesartan plus HCTZ. In an optional extension patients with uncontrolled BP at the end of the core study can be treated with valsartan plus HCTZ in fixed dose combination plus amlodipine 5 mg for additional 4 weeks.