Help. Air Handler dripping water into secondary drip pan…

I have a Bosch AC/Heatpump unit outside and a Bosch air handler in the attic. We live in the North East and just had a bad heat wave. When I got home last night the upstair AC was not running. So I went up into the attic and

checked the secondary drip pan. Sure enough there was water in it and the safety switch tripped and shut the unit off. I opened the panel to the air handler and the bottom inside insulation was soaked. I was not happy.

So I called the HVAC company and they came out this morning and spent some time here. Here is what was tried.

1. Poured about 3 gallons of water in the drip pan inside of the unit to make sure the drain was not clogged. That worked fine with no issues.

2. Checked the air filter to make sure it wasn’t dirty. I am religious about changing it so I knew that would not be a problem.

2. Tested the refrigorant in the outside unit. That was completely fine

3. Tested the air flow in the air handler for something called negative pressure? Wasn’t really sure what that meant but that was fine.

4. This is also a Hydro-Air unit so checked the heating coil and pipes to make sure that wasn’t the issue. Those were all fine.

So at this point nobody is sure what is happening. So we left the panels off the unit so the inside could dry out. The only thing he can think of is that

if there is a crack somewhere in the main drip pan in the unit. But since it was already soaked inside he couldn’t tell when we poured the 3 gallons

of water in it if water was getting through. So they are going to come back next week after everything is dry and pour a bunch of water in the main

pan again to see if it makes the inside wet. Then he will know that is the cause.

But if that does not work, does anyone have any idea what else can be tried. The outdoor and indoor unit are only 2 years old. I am now worried about a bunch

of mold growing in the air handler and my family breathing it in.

Thanks for any help,

Derek