Boiler not delivering enough hot water

[sarah_louise]

My Worcester Bosch Combi Boiler about 12 years old.
The Central heating is great. You cant touch the radiators they get so hot If I want them really hot. When I run a bath I get really hot water for a few seconds then luke warm water then really hot water etc...etc... The overall effect is a bath that is not quite hot enough. I do not run the cold tap at all obviously.
The hot water thermostat has been changed. A diverter valve has been changed.
Any ideas ?

[Big Al1st]

Hi Sarah, Could well be the heat exchanger which can clog up over the years. Dunno how much they are but an Engineer can change one in about an hour. We had similar problem Al