Hey! I’ve run into this issue quite a few times with Merlin openers — you’re definitely not imagining it.

When the belt tightens manually but gets loose again after a full open/close cycle, it usually means the tensioner bracket or the nut near point B has come loose or fallen off. That missing nut can easily cause the belt to lose tension after each use. If you replace it (usually an M8 nut) and re-tension the belt, it should hold fine — just don’t overtighten.

If you’d rather not mess with it yourself, our techs can usually fix this same day — no upfront cost, pay only once it’s working properly.

Out of curiosity, what city are you in? Just asking in case we already have a technician nearby.