The dryer issues the error E4 and stops working.
What is the reason and what should I do?
I don’t know if you’ve got it figured out yet but if not your motherboard will need to be replaced. It isn’t difficult to do. I’ve been going through this for weeks now. I replaced mine once & it worked a few days then the E4 came back. Creality sent another board & it has an E2 immediately after startup.
There is a design flaw, a component flaw, or both in these units. Creality needs to fix the problem as it’s not uncommon. Three bad boards for me alone & I need a 4th or hopefully a new dryer.
Yes, a new board has already been sent to me, I replaced it.
This error just because dryer not reach expected temperature in expected time period. You need to close the cover when you switch it on. Or, sometimes, placement of the temperature sensor not good, needs to bend it legs.
I think that error can be caused by the dryer being started in a cold environment