I HAVE A PERFORMA 28i which when on hot water only it
stays on continusly and does not switch off.
The boiler ignites for 10 seconds fine when tap has been running then goes out but the water only light stays on and sounds like its still running. the neon lite does not flash when in operation it just comes on and stays on can you help

simon batstone, June 2007

If i remember correctly this model has a pre-heat facility and this is usually indicated by a flashing light at the hot water symbol. You say the neon isn't flashing but have you tried to switch the pre- heat function off?
If you have and it is still running on it is probably the micro switch on the water flow switch sticking in the run position after the tap switches off.
The book should tell you how to identify the right switch..

T.h.s, June 2007