Vaillant Boiler turning on randomly?

My Vaillant turbomax boiler used to do this. From reading the instruction book it is an option called Warmstart which keeps the water in the boiler warm ready for when you need it. You can turn warmstart off by rotating the hot water temperature dial all the way to the left and then back to the right. If you want it turned back on again just turn the dial all the way to the right and back to the left. I found it didn't make much difference in the time it took hot water to get to the taps so I turned warmstart off.

Alison
September 2008

Some boilers have a small amount of hot water stored and will fire up occasionally to keep it topped up. You should be able to turn this feature off but it could mean that it wil take a little longer for the hot water to come through to the tap.

ex (thank gawd )british gas engineer
September 2008

is it set to eco on the front ?
if so it will fire up every now and then to keep water to temp.

hi-spec plumbing & heating (essex)
September 2008