May well depend on the make & model of your boiler, if the water is too hot or too cold, if it's the water in the radiators or at the taps - so many things left unsaid.
Perhaps it might be best to call a boiler engineer - he can gently tease the information from you.
Godd luck...
Peccavi
November 2009
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.