Our boiler has started to fail firing up on the evening timed hot water cycle. Also, when I press the 'advance' button to kick start it, nothing happens. I have to switch the heating on (which we don't currently have on at the moment due to the summer) and this seems to trigger the boiler off to heat the water.
Is this a problem with the controls or with the boiler?
Our boiler is a British Gas 450 RD2 and the controls are Drayton LP112. I'd say the boiler was installed around 2003 and was last serviced approx March 2013. We regularly need to change the thermistor harness but I think this probably a separate issue to that.
Thanks