I think that's the point, that mixture will kill everthing in your condensate line so you will never have a clog. It essentially fumagates your drain.

I'm not recommending that, only this is what one neighbor swears by.

Surprised in this discussion that no one has been putting Dawn liquid in their condensate pipe followed by warm water. This is the recommended procedure we have gotten from our Trane installation company.

The Trane website (trane.com) does not recommend using Dawn liquid in the condensate drain. They recommend using a mixture of water and vinegar to keep the drain clear.

Note that Carrier does not recommend using vinegar. They recommend using only warm water.

I think if you maintain your condensate drain by pouring hot water down it once a month or so, then you don't need to add any other chemicals since it will be basically clear of any algee or other growth. There will be nothing to "wash" away. But if you haven't maintained your drain and now decide to do it, then you probably want to flush it out with some soap or mild chemical to get it clean.

I'm surprised that no one has mentioned this device. Anyone using it? Once you by it for $99 then it's $44/year for the solution.

Amazon.com

I like to use these:
Amazon.com

I just saw another thread here on TOTV about using the iFlow device so no need to comment. From what I can tell everyone has their own special formula on what to dump down the drain each month to keep it clear.

The iFlo is a good idea but there really is no good way to get the solution into the evaporator drain pan and I'm not convinced the small amount of fluid it dispenses down the drain every two weeks is as good as dumping a gallon of hot water.

It appears that bleach will attack the PVC and vinegar the evaporator coils so hot water seems to be the solution as long as you do it every month or so.

Is anyone using the drain pan tablets? If you take out the filter on your air handler you can reach in and put them in the pan without taking off the cover. The only thing is they say they only last about 3 months. I remember Sunshine putting these tablets in the pan when doing maintenance then at the last visit they poured some solution down the drain after flushing it instead of using the tablets. My guess they feel they are cleaning the evaporator coil and pan when they come so no need to put anything in the pan, just the drain to keep it clear. Any thoughts on this? I think Munns does the same from what I saw when they did maintenance at my friends home.

my original 18 yr. old unit only drinks hot water.

I could be wrong, but I think adding dish detergent to the condensate drain could cause more problems than it can solve. This is because you cannot see how much water to add to completely flush out the suds, and it could actually cause a clog. Technicians will sometimes offer advice that is not consistent with the official recommendations of the equipment manufacturer.