We first purchased a Nolting, used from a person in Kansas and we called Nolting and we talked to Dan Novak their technician. He talked us through repairs such as unscrewing face plate to untangle thread, taking some very fine sand paper to take a burr from the needle hole, running thread through batting (so it wouldn't tangle) and checking the timing after a needle was broken. When we needed to have it serviced we sent it to Iowa and we decided to upgrade they took ours as a trade in. So, I have nothing but good things to say about Dan and Nolting.
I know how frustrating thread breakage can be. We used Signature thread (it was particular about thread) and It does not like a quilt to be too tight as other have said.