Blocked a/c condensate drains

[Reefgeorge]

The foam block belongs in the pan, it keeps the drain water from sloshing around. I have never been able to get lasting results with a shop vac on a drain line, I always use water flow in the apposite direction. There are all sorts of tablets for this containing various combinations of algaecide, sanitizer, etc but I have never used any of them in boat or house. Be very careful with any chemicals on the evap coils like chlorine, acid, act. As has been pointed out, you might damage the metal and get leaking.

My program is a good electrostatic filter sheet on the return air to keep the coils clean, and if necessary, clean the pan and or back flush the drain line with water pressure.

George

[Westfield 11]

Thanks for all the good advice. I’ve treated one of the pans with a commercial a/c drain line cleaner and another with white vinegar and will see how things go. I also cleaned the evaporator coils while I was in there. Right now all are draining correctly.