Geeetech

Probably bed is not flat. Get my A10 profile and when it does circle about object, you can fine.tune bed level.

From front side view of bed knobs:

turn ===> to make bed low
turn <==== to make bed high

One whole turn is 0.5mm.

You can also check Y axis wheels, if you can move your bed left and right or up and down, they need to be adjusted. If they loose bed leveling will be compromised.

Hi,For nozzle clogging cleaning you can refer to this: http://www.geeetech.com/forum/viewtopic ... 98&t=68671
Regarding the hot bed problem you can remove it to see if it is level.