The number of jars should not have made any difference. I have an A-A and I know sometimes if I don't ratchet the lid down just so there will be some leakage and it won't reach pressure.

So in those cases, the first thing I would do is turn off the canner and once it's returned to zero examine the lid and re-set it, being careful to make sure it's level and tight all the way around.

Carol

The number of the jars in the canner makes no difference to the canner. As far as it is concerned it doesn't care if it is 1 jar or 7 jars. It evens works the same with only water and no jars.

So something else was wrong. Stove burner not working properly? I have had a burner partially fail on me before so it wasn't heating properly even though it was set on high. Steam vent plugged up perhaps? Weight not sitting level or correctly on the stem? That is the most common - weight not sitting level or on correctly.

Dave

Usually find if there is difficulty reaching pressure that the gasket isn't seated properly.

AA doesn't have a gasket - though maybe lid wasn't clamped down evenly as Carol suggested? You didn't see steam leaking from one spot did you?

I found my Presto was taking a long time to come to pressure last night with 4 quart load.