Flush Valves Replacements and fill valves replacements for Toilets for repaires. Range of replacement Flush Valves, whether pneumatic or mechanical, single or dual flush, you will find it in this section. Fill valves and floats to replace toilet filling mechanisums. Fill vales and flush valves are also known as Dump & Drop Valves or Flush Mechanisms. At Rubberduck Bathrooms we stock a range of the most commonly used flush valves, replacement flush valves, fill valves and cisterns.