Ariston Microgenus 23 Combi boiler turns itself on

[KennOz]

Hello

I recently had an annual service on my boiler and then a few days later, when arriving home from work, I discovered the boiler was "running". It had somehow turned itself on.

The heating was off and of course no hot water was running. This still happens from time to time (not a lot but it's annoying), where the boiler seems to "power up". Someone suggested it may be the circuit board (cross wires? something short circuiting?).

My usual plumber (Gas Safe) isn't able to come and attend to it so I have arranged for another plumber to look at it next week. for peace of mind though, and in case it's a simple switch I can flick to save the money, is there anything obvious which might solve the problem?

Thanks!

 

[picasso]

If you look at the control on the front of the boiler you will see a knob with "E" and "C" written above it, if its on "C" the preheat has been turned on if you dont want the preheat turn the knob to "E".