Whats wrong with my Vokera Mynute EHE boiler?

Wonder could anyone kindly help. I have a Vokera Mynute EHE boiler fitted in my home, which until recently was working just fine. It now only works the central heating and does not heat the hot water. The pressure seems fine and there are no fault indicators showing up. It is worked by a Horstmann Channel Plus H37XL control panel mounted on the wall beside it (if that makes any difference). Any help would be greatly appreciated.