Error 3 Belling IDW604 Dishwasher?

The cycle is showing error 3 which says the fault is either the heat sensor or the heating element. Basically the water for the rinse is not getting hot enough so dishes are unclean at end of cycle. it's out of warranty and don't want to incurr call out charges if I can help it.

This appliance is just over 12 months old and I haven't even used a full box of tablets so it's hardly been used either.