Jim B wrote:
My first questions to the shop would be "Did you disconnect the vac from the
AI in any way when you changed the DG?" and "Did you blow out the
(hopefully new) DG hose before you re-connected it?

That's why it's back at the shop. I'm thinking that something got
into the AI connections.

As the AI is above the DG, the AI hose and even the AI itself may have been
in their way if they accessed it from the top. It could be as simple as
they cracked a T fitting or a hard hose.

Please, let this be the simple problem with a simple solution.

Something is preventing the AI from erecting, could it be low vac suction?
What does your suction gauge read? Could be weak springs in the AI simply
waiting for a day to show you they are tired.

Both the DG and the suction were showing good numbers/reactions. The
AI was installed in 2003 and was brand new. I'm hoping that it would
last more than 5 years.

But it's snowing here, so there's no rush.