Siemens Hydro Sensor – no hot water, any ideas ?????

Our 3 year old Siemens Hydro Sensor free standing dishwasher appears to have developed a fault.
All the lights and buttons still work, no error code is showing and the full wash cycle is completed with no drainage issues.
During the wash the door is cold to the touch, at the end of the wash cycle, the plates are not properly clean, all still soaking wet, all cold and no steam at all so i am guessing there is no hot water being produced during the wash. The display also won’t clear itself at the end of the cycle, it still shows 1 min to go even thou its finished. Press the reset buttons and it clears, not sure if its related but thought it worth a mention.
Checked for blockages and all ok, tried all 6 different cycles and all the same problem. Any ideas what could be wrong and is it a job for the competent DIYer (managed to swap the defrost sensor circuit on my Samsung fridge/freezer with help from the forum). Is it as simple as a faulty heating element

Model number (not sure which one it is on the name plate so best give you all of them)
SE25 A09 1GB/24
TYPE 59VT1S
013110330692002867

Thanks

Phil