Firstly thanks for all the help with Z axis I have recalibrated and all is well.
I have had problems with blockages between the extruder and the hot end where filament has harden in the heat exchanger tube. I have used the wire plunger supplied and heated it to melt the blockage with little success. I now know to use the plunger immediately after retracting filament. I hade to take the hot end apart a few times to clear blockage but on reassembly I have not been able to get a tight fit between the nozzle and heater unit so when printing molten filament is running down outside of nozzle and blobbing onto print making a mess and buggering the print. I have ordered anew hot end, nozzles and silicon cap but have to wait for delivery and I have customers waiting for their prints. Please Help.
Thanks Bruce
Is the nozzle tightened all the way up as far as it can go…?
It should retract the filament without getting blocked up…
On the top of the hotend make sure that copper part is screwed all the way in also…
It’s important to not just screw the nozzle into the hotend, but to tighten it while it’s hot. Heat the hotend up to 250°C, counter the heater with the wrench that comes with the K1 so that there’s as little torque as possible acting on the hotend mount, then carefully tighten the nozzle against the heatbreak and low it cool down again. Do not use too much force, the hotend could snap off, turn in with feeling.
Thanks working well now
Good to hear it’s back working again… !
What was your fix to get it working right so others might be able to get theirs running…? 
The problem was that there was hardened filament residue in the thread of the heat block that prevented the nozzle from screwing in correctly, so when i began to print again it would melt and leave a gap where the melted filament could get through and run down the outside of the nozzle and cause blobs on the print.
The fix is easy: before screwing in the nozzle heat up the hot end so it melts any residue and the nozzle will screw in tight just remember to use the spanner supplied to hold the hot end and the spanner for the nozzle