No as some modern type have a cuptype float that rises up a toothed/rachet shaft. Just keep eye on it see if it turns itself off.
1. If there is a stopcock /check valve in the cistern feed pipe .it may need opening more for a faster fill.
2.Unlikely but the washer could have stuck over the water inlet in the inlet valve and meeds replacing.
3. The whole inlet valve may need changing.
BB, November 2009
