transistor identification

hi to all, i am very new to this, but can someone please help me.
i have a pcb out of a coffee machine and a transistor has overheated so i go down to maplins to get a new one and the guy tells me that there should be a code on it so we can recognise it, but i doesn't, there are 2 other transistors that look the same they also do not have codes on them.
first question, are the transistors going to be the same?
2nd is there another way of recognising them ?
thanks in advance if anyone can help
dave

You really have to draw as much of the circuit as you can and post it on this site.
The most important point is to show the voltage of the supply so we know the voltage-rating of the devices.

That transistor could also be a triac. I agree with colin55 - without a circuit diagram, there's not much help available.