clock slowing down on combi boiler

rammster

I have a vaillant combi boiler with clock function. This was installed 6 years ago. I have just moved into the house and found that the clock slows down so the scheduled heating times dont work. As this was installed by the homeowner previous to my seller , I am not sure whether there is a comeback here. I have looked at vaillant manuals and couldnt find any mention of any batteries in the clock. Which makes me wonder whether its attached to the main supply to the boiler.

What should be my next step. I have moved in only 2 weeks ago.

eco-friendly_2

some digital clock/timers use the mains cycle ,
switch the boiler off at the mains for 5 mins and reset the clock, worth a try !

> What should be my next step. I have moved in only 2 weeks ago.

normally you only have a few days, for a comeback.