Skimmer crapped out....where to start troubleshooting

[Coralgurl]

Is it normal after cleaning out the skimmer - vinegar bath - for it to overflow? It's been running for almost 2 days and it won't settle back down. I've pulled the plug on the cup so it's just dumping back into the sump but no matter what, it keeps over flowing. I couldnt rinse it after, just soaked in plain water, I've done a water change but no difference. I'm leaving for a week tomorrow, the tank and inhabitants are all fine, but I don't like leaving it like this....