Advice on a combi boiler needed

[michael_v2 10]

Our boiler is a Ravenheat "the white star" combi boiler. To start with, our combi boiler works. The central heating works perfectly when it switches on. The problem comes when the central heating is off and we need some hot water.

 

When the tap is opened and water flows, the boiler clicks into life and you get hot water after 10 seconds or so. it lasts for 30 seconds and then hot water goes off. If the tap is left running it eventually comes on again, but repeats the same process.

 

I can hear the boiler come on, the flame light and after half a minute there is a tinny type of clicking and it goes off. I'm hoping that it may be a fault with the switch that works when the water starts flowing. we're just about to have a mixer shower fitted and really needs the combi boilker to work at its best.

 

Sorry to ramble but need advice soon. Thanks