it could be quite a number of things, if you have just moved in it's maybe a good idea to have your boiler serviced anyway (god knows when it was done last) and you service technician should be able to sort this out.
Could be anything from a lack of a restricter on the water feed, to filters blocked, partially blocked heat exchanger......and on and on
Most modern boilers say in the instructions that you will achieve a 35deg rise in temo. from inlet water temp. and a particular flow rate, your service tech. should check this with a flow meter and thermometer for you if you request it.
T, April 2008
