It is not heating

Hello,

I had this problem one time. In my case it turned out to be the ceramic heating element. Hakko should be able to either repair it or send you a replacement part. If it is new, contact them and ask what your options are. If it's been in use for a while, you could check the ceramic by unscrewing the retaining nut that holds the hot end and carefully slide off the steel sleeve and inspect the ceramic. The ceramic is very fragile, so be very careful just in case it's not broken and the problem is a different component.