if the belt is not worn out to much, it possibly could be tensioned very easily, as described in this video by @fbrc8-erin:
As the sliding blocks (which contain a build in tensioning spring) at the UM2, UM3 and S-Series are the same, this procedure might work for your UM2 as well.
It would be also a good idea to check the play on the axles and -if needed- calibrate the print head as described here:
Belts are replaceble, and the procedure should be somewhere on the Ultimaker-site. If you are a bit handy, you can do it yourself. Your local dealer should be able to provide the belts. Or you can have him/her do it.
While you are at it, I would take the time to have a look at the feeder too: is that clean and in good condition?
Also clean the metal rods near the belts, and lubricate them with a thin oil that does not dry out.
And also clean the nozzle with cold pulls or "atomic pulls". See the official method on the Ultimaker-site, or use my gentle method here (I am no Ultimaker-staff, just a user):
And check if the white teflon coupler above the nozzle is still okay, not deformed, not burned.
Link to post
Share on other sites