Timer getting stuck on Worcester Bosch

[MarcMCFC1986]

I have a Worcester Bosch Greenstar Junior 28i - and a few weeks ago the timer kept getting stuck after about 10/11 hours.

I changed the MT10 Timer but it is still happening, so wondering what the next step is to get it working properly?

 

[RandomGrinch]

what the next step is to get it working properly?

Send it back if it's faulty, or...
Set it to permanently on, and install a smart stat, or external timer?

 

[ericmark]

There is a built-in clock option

and the MT10

is one of the options, but the instruction manual simple says plug in ribbon cable. There seems to be a distinct lack of info as to how it works.

External controls easy, but you would need a Bosch agent to know how the timer works.