hi i'm having the same problem as you. i first posted a message simular to yours and was told they need lots of information to help, so thought this would help. this is some of the information they need.
1) Boiler make / model (gas or oil)
2) What is / is not happening
3) Has ANYTHING else been done / changed recently
4) When did it (problem) start
5) When does it happen? eg, heating coming on or going off
Comon fault on the 280 Worcester is the diverter valve not working. Drop down the controll panel and look at the white diverter valve body you should see a small black button between A and B when you switch on the cental heating it should move across from one to the other, check the demand light comes on and if so then you will prob need a new valve if you want to make check it should have a 240v supply when activated if so and no movement then it is up the shoot.
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