Got called to this big house, zone system acting up. I found this gem waiting for me:

Note the blank spots, everyone and his brother have been working on this mess. 5 ton drive Rheem, single side return with an EAC. So, already it's sucking for air. How can we make it worse? Oooh, let's ZONE it! Sloppily installed California Economizer system. Note the bypass damper on the right dumping unfiltered air into the blower:

The weight is also set so that it will never open. I had one single zone operating for a half hour and the damper never even fluttered.

The humidifier has been leaking for a while, note the water line secured down to the metal with thumb gum.

To top it all off, I can't find a zone panel. Why? Oh, because there isn't one. They wired it like so:

The customer was very proud of this job, he was bragging to me that the engineers at Rheem flew in to design this for him. I tried to explain that if Rheem saw what they did to this unit they'd have his warranty voided, but I guess he didn't want to acknowledge that he paid for this.