Should not be any problem DIY. But,do it after the winter. because the heating must shut off to do this job.
However, what you can do now, look around the blower fan compartment, it is easy to spot the fan bearing, if don't see any bearing, it may be just a Bronze Bushing (套筒軸承) add some oil to it.
Also have you clean the dust/air filter regularly?
However, what you can do now, look around the blower fan compartment, it is easy to spot the fan bearing, if don't see any bearing, it may be just a Bronze Bushing (套筒軸承) add some oil to it.
Also have you clean the dust/air filter regularly?