re: Ac secondary drip pans have no drain…should they?

quote:

---

Could I just run and T the AC secondary pan drain into hot water heater drain line

---

You could but I wouldn't waste your time. If the float switch in primary fails and water does end up going into pan and into drain line, you'll never know things need attention unless you just happen to see it up in attic. Or eventually the second line would clog and then you'll see it in the form of water on your ceiling.

Have a float switch in primary and if/when that fails, a second switch in emergency pan.

I wouldn't bother with a water alarm but if you do, probably best to use lithium batts since alkaline would quickly fail in a hot attic. Water alarms are great for under sinks, dishwashers, fridges,ect.