Your inside coil should have two outlets to drain condensate one running outside and the other with a float switch to shut down the unit if the outside drains clogs.
Condensate pump drain line frozen.
The best way to stop condensate drain line freeze is to use weather proof sleeves placed around the drain.
During periods of snow verify that snow hasn t risen to the level of the drain line where it can block it and cause further freezing.
You can unscrew that float unit and put a bucket there to drain the condensate until the line thaws.
The vast majority of your condensate line should be inside your home where it s warm.
I added a secondary shutoff if the new pump fails via a float switch.
Last night my heat forced air suddenly stopped.
The condensate pump will only come on if the outside gravity line freezes.
Cut your condensate line close to your house so the water drains before freezing.
Shortening the drain pipe to give water less space in which to freeze can also be effective.
How to prevent frozen condensate drain lines.
It pumps it out only when the drain line is frozen.
If you already have a frozen condensate line this is an easy fix.
Today a plumber figured out that my heater is 90 efficient produces lots of condensate and the drain line had frozen.