TYBOX 827 RF Service due reset?

I have a Delta Dore Tybox 827Rf connected to a Greenstar 30CDI boiler, now the bolier has been serviced and the service schedule reset but the Tybox has also got a service reminded which we cant seem to turn off, now its been more than 30 days since the Tybox service reminder has appeared it has shut the hot water off!!!!! Any ideas as how to re set the service reminder on the Tybox???
Thanks in advance folks