*NOTE: This blog post applies to 1st Gen. WatchDog Dehumidifiers. For help with maintenance on NXT Dehumidifiers, check out this post.


If you want to keep your new dehumidifier problem-free it’s extremely important to perform maintenance on a regular basis. Without consistent cleaning, issues can start to build up, preventing your dehumidifier from running effectively or even running at all. To avoid these problems, all you need to do is simply clean the parts listed below. Before beginning any maintenance or repairs, always remember to turn your dehumidifier off and allow it to shut down completely. It can take up to a minute for the unit to power off.

Tools Needed:

• Self Rinsing, Foaming Coil Cleaner (such as WEB Coil Cleaner)
• Cleaning Solution
• 1 oz bleach mixed with 15 oz water OR 4 oz white vinegar mixed with 12 oz of water
• Approximately 32 ounces of water ( two 16.9 oz bottles works well)

1. Cleaning the Filter on the dehumidifier

Once the unit is turned off, the next step is to clean the filter. The WatchDog 900 and 900c both come standard with a prefilter. The prefilter is washable. To clean it, slide the filter cassette out of the machine and gently remove the prefilter. Next, rinse the prefilter with water to clean any dirt or buildup that has accumulated. After rinsing, shake to dry. Alternatively, you can vacuum the prefilter to clean it. The 900 and 900c can also be used with a MERV-8 filter which is washable.

In addition, there is an option to use a carbon or HEPA filter which is not washable. Simply check these filters for build up and replace as needed.

The WatchDog 550 comes standard with a MERV-8 filter, which is washable with water or vacuuming. There are also two optional filters: carbon or HEPA. These filters are not washable.

2. Cleaning the Coils on the dehumidifier

The next step is cleaning the coils. To clean the coils, you will need to use a self-rinsing, foaming coil cleaner, such as WEB COIL Cleaner. Spray the entire surface of the coils with the spray, then let sit for 5 minutes before moving on to the next step. There’s no need to rinse the cleaner off of the coils since the dehumidification process will do that for you.

3a. Cleaning the Pump on the dehumidifier{Watchdog 900c ONLY}

If you have the 900c model, you will need to maintain the condensate pump as well. To do this, first push the drain button to empty the reservoir. Next, unplug the dehumidifier and carefully pour the cleaning solution into the drain tray. Allow the cleaning solution to soak for 15 minutes then plug the dehumidifier back into power. Add 32 ounces of clean water to the drain tray and allow the pump to cycle through at least 2 times to flush out the cleaning solution.

3b. Cleaning the Gravity Drain on the dehumidifier{WatchDog 900 and WatchDog 550}

If you have a non-pump model, you will need to clean the gravity drain. First, pour the cleaning solution into the drain tray. Let soak for 15 minutes, then flush the drain line with 32 ounces of clean water.

Completing these 3 basic tasks will help to ensure your dehumidifier has a long and effective life.