Food Saver problem

We have a Food Saver Vac 550, which we use for vacuum sealing our food for trips. We've had no problems with it until now, and follow the directions exactly. They usually seal just fine, but recently we've had the problem of air getting back into the bag when left overnight. We're using the bags that go with the machine. Any thoughts as to what might be wrong?

If it's happened more than once it's probably not something you did and if it was the bag I don't think it would vacuum.
It sounds like the sealing strip may not be working properly.
I would seal in some ice cubes, melt them and see if the water can be pushed out through the seams. It might not be visible right away, maybe some starch or baby powder will help it show. If there is a leak I would check the other side and see if it's in the same area.

The directions that came with mine were no help other than listing:

1-800-777-5452 Customer Services.

Hope this helps some

Is the seal completely dry? I've had the occasional issue when the meal I've saved is a bit too watery. The vaccuum looks tight, but by the next evening a little air gets in there. It's not enough that I have to toss it.

Yes, use a full length bag (do not shape/shorten) and like DUG said try w/ a completely dry bag & meal. Only then if it malfunctions would I suspect a problem with the unit.

There was indeed a problem with the vacuum sealing strip - a small bump on the surface which prevented a tight seal. I called customer service. The representative suggested that I use a credit card to try to move the bump, which would indicate that food had somehow lodged itself under the sealer screen. The credit card procedure indicated that there was a solid mass which couldn't be moved. The sealer element is not replaceable so......... we purchased another vacuum sealer which works like a charm. What is disturbing, is that I took meticulous care of this appliance, followed all of the instructions TO THE LETTER, and still had this problem. Oh well - since I'm in the process of making dehydrated meals for our trip to the Grand Canyon, vacuum sealing is essential. Hopefully, we'll have this unit longer than 2 years. BTW, we bought another FoodSaver.

Edelweiss

By the way, thanks everyone for their good suggestions!