My dishwasher blows the mains electrical fuse every time i turn it on it is a zanussi model da 6142 ( 6 mths old )

If you are not knowledgable in electricity, call for service.
This is an electrical short at the light, I have seen this before.
The wiring for the light has grounded to the oven. This causes the main fuse to blow. You will need to fix the short first. Then reset the main fuse/replace.
In the case of the wall oven, you may have to remove the oven to fix it properly. Depending on the model and where the short is.

A guess is that the water has leaked into the motor, and the machine is shorting out.
As a retired firefighter, may I please recommend you do not try to start it again?
It could start a fire.
It is probably time to buy another dishwasher.
Be blessed.

the grill element needs replaceing or you have a wire on the grill element thats come off and touching down to earth

If the plug is oerheating, then I suggest you fit a new plug, and make sure the connections are good.

Was this all of a sudden or was it going through a cycle at the time?Have you checked that there is power at the powerpoint?

This is happening because you have a very bad fault, a Phase to Earth short, problem. Leave machine UNPLUGGED, Breaker/Fuses OUT. do NOT use it, nor Touch it, It is possible to get severe electric shock. PLEASE get a registered serviceman to inspect this unit.

This is not a valid model number, however, all appliances have a wiring diagram/schematic attached to the chassis or affixed to a door/access panels.

Your dishwasher may pre-heat the water. If so, and if the water entering the dishwasher is cool, the heater may take up to half an hour to heat the water.

To avoid the wait, increase the incoming water temperature before turning on the dishwasher. Do that by running the kitchen sink faucet until the water runs hot. Or increase the temperature of the hot water to the entire house at the hot water heater.

I would disconnect the heater element.When you turn the unit back on and all is ok the element is bad if not the pump motor is your problem.

Check first the filters on the inlet water line (both sides). Then, if problem still exist - check that the inlet water valve works(it is an electromagnet valve, located at the pipe's entrance to the machine)). If it doesn't work, test that it get power. In case it get power and doesn't work - You can easily open the valve and clean it (from scale or other dirt). Be aware you should disconnect the power cable from machine before doing it !!!! Check as well for valve's coil resistance. In case you have no resistance measurement - you should replace it for a new one. Good luck