Gariep

Hi everyone, I have an Ultimaker 2 extended+. I let the printer run overnight to find it stuck and clogged this morning. The whole block was surrounded with nylon. I tried to heat the block to unclogged it but the light flicker and the printer shut down after a few seconds of heating the block. I guess there is a short in the cable caused by the hot nylon that melted the cable. I managed to remove the heater and heat sensor. I tested the resistance of the heater and I get 1.2 Ohm (heater is cold) Is this a normal reading? Should I change the heater? I would also like to change the block. What do you suggest and where can I buy these parts? I'm in Canada. Is it possible to upgrade with a better head design or with the Ultimaker 3 interchangeable head? Any suggestions are welcome Regards