Condensate Drain Cleaning

It is time for annual spring AC maintenance calls. One thing you should be doing is cleaning out the condensate line and checking to see that the condensate drain is working properly. The customer is paying you for a seasonal maintenance to avoid having problems – such as a mess caused by something as simple as a clogged drain line. If you can get to the condensate drain easily, you can blow it out with nitrogen using a rubber stopper with a 1/4” copper pipe and flare connection.

Gallo Gun

Another option is the Gallo Gun that uses CO2 charges. Both of these options require access to the drain opening inside the evaporator drain pan. The drain opening is usually accessible on cased coils by removing a panel on the front of the coil casing. Likewise, the drain opening for the coil in most heat pump air handlers can be accessed by removing the front panels.


However, for coils in hard to reach places, or coils installed inside a plenum with no access panel, it may be easier to suck out the muck using a Sludge Sucker. The Sludge Sucker is installed on the drain outlet. Nitrogen pressure creates a vortex which makes a strong suction on the drain line, sucking out the water and muck in the entire drain system.

Uniweld Sludge Sucker

Foe some systems you may need to clean out the condensate line trap. If  the drain is already plugged, then chances are the trap is plugged. Most manufacturers require condensate line traps. The trap is designed to stop air from sucking in through the condensate line during operation. Unfortunately, because traps tend to trap stuff, they get blocked with crud. Most codes now require that condensate lines have clean-outs which allow the trap to be cleaned without cutting out the existing trap and replacing it. For many site built traps, this has been common for many years. The only practical way to clean them was actually to just replace them.

If you do have to cut out and replace a condensate trap, make sure that what you replace it with can be opened and cleaned. This can be done by installing tees in a couple of places where you would normally use ells and plugging or capping the unused branch. Alternatively, you can use a manufactured product such as the Rectorseal EZ Trap of the All-Access AA1 cleanout.

Rectorseal EZ Trap

All Access AA1

Another solution would be to remove the traditional trap and replace it with a product designed to provide a drain seal without trapping water. Three types are available – the Cost Guard condensate drain seal by Trent Technologies, the Air Trap by Des Champs Technologies, and the Rectorseal Waterless Kit for their EZ Trap. I will talk more about how these work in a future post.

Trent Technologies Cost Guard

Des Champs Air Traps

Rectorseal Waterless Kit

If the system you are working on does not have a safety overflow switch installed, consider adding one. The safety switch is typically wired in series with “Y” to prevent the outdoor unit from operating and creating more water.  Some are installed in the primary drain clean-out, and some are installed in the secondary drain port. They are inexpensive, easy to add, and help prevent property damage. In the case of coils installed on top of furnaces, they can prevent the destruction of expensive electronic components inside the furnace from an overflowing condensate drain.

Rectorseal Safety Switch in primary drain

Diversitech safety switch in secondary drain