Brand new plasticky boiler arrived last week!

Could hardly wait to get going for the first time, everything went as it should and ending up with about 20l of lovely smelly wort I stood back and waited for the beast to boil as my new toy rumbled and growled as it heated up.
Then a sudden silence

I waited & waited,after an hour of silence and no rise in temp from the 76 or so degrees it had got to I was becoming suspicious.
I emptied the contents back into the bucket in an effort to find out the cause of my problem. Wires all seemed ok and after chucking a couple of litres of cold water in, the beast stirred back into life.

Ok, must have been a loose wire, away we go again 76 degrees later off it went again! I drain off once more recheck everything again and yes you're ahead of me, same thing happened again. By now I'm seriously Peed off so I chuck everthing in, swirll it around and three days on it's bubbling away, though what I get remains to be seen. I think the elements cut out thingy must be stuffed 'cos I've tried it a couple more times with water and it does the same thing every time.
I'm now waiting for a new element to come.
When it gets here I'll have another go!!