When i turn the hot water taps on any where in the house, i might get hot water for a minute or two then it goes very cold,This doesn't happen every time.
Last night was O.K but this morning same problem.

The make of combi boiler is Worcestor 28CDI

Alan Parsons, August 2008

check your flow rate before you go any further

paul, August 2008

You need to turn the tap on more fully, you will find the boiler doesnt switch off and cut the hot water.
Basically when the stem of hot water slows from the tap turn it up! This is typical of modern combi, esp.Bosch. The title of your question says, long time for water to come through, this is also normal for modern combi, fill your kettle with the wasted cold water.

Jex, August 2008

when you turn the taps on does the boiler fire immediately? if not the divertor valve sounds likely. if it does fire but then go out the dhw heat exchanger sounds like it may have a blockage on it

kieran, August 2008