How to Clean RV Drain Valves

How to Clean RV Drain Valves
Cleaning RV drain valves is a regular part of routine maintenance. These valves control fluids that accumulate in the vehicle's black and grey water holding tanks. When connected to waste hoses, open the drain valve's release waste to sanitary dump stations.

Thoroughly cleaning valves will often result in removing debris of one type or another, the largest part of keeping drain valves free of debris is by cleaning the tanks that feed them. Requiring a minimum of effort and time, cleaning your RV drain valves ensures that you will spend more time enjoying vacation and less time repairing your RV.


Difficulty: Moderately Easy

Things You’ll Need:
  • 2 cups fabric softener
  • 1 cup laundry detergent
  • Holding tank cleaner
  • Tank deodorizer
  • Rubber gloves
Step 1
Keep drain valves closed until tanks are full to avoid congestion due to solid waste when parked and when drain lines are connected. Do not leave drain valves continuously open, as fluid will drain, leaving solids that can then harden and block drain valves.
Step 2
Use additional water whenever flushing solid waste. This decreases the chances of a clogged drain valve when emptying the tanks later. Flush the toilet while pouring a small bucket of water for best results.
Step 3
Dissolve two cups of fabric softener in one gallon of hot water. Pour the entire mixture into a holding tank, repeating the process for each tank. Add one cup of laundry detergent to the black water tank for additional cleaning. Close drain valves before pouring the mixture. Continue to use the tanks as normal until full and then open the valves to drain.
Step 4
Dump the dirtiest tank, the black water tank, first. Then dump the gray water kitchen tank, shower and bathroom sink tank. Avoid dumping the black water tank last, as solid waste may clog the drain valves.
Step 5
Use a water filter on the freshwater tank line to decrease sediment build-up that may clog drain valves over time.
Step 6
Pour a holding tank cleaner that is enzyme based down all drains once a month. This dislodges bacterial growth from tank walls. Pour cleaners before bedtime and drain in the morning.
Step 7
Slip on a pair of rubber gloves once tanks are completely emptied. Inspect drain valves and directly clear any debris.

Tips & Warnings

Use a tank deodorizer for any lingering odors.

Article Written By Mike Biscoe

Mike Biscoe has been writing since 2009. Focusing on travel, sports and entertainment topics, he has credits in various online publications including LIVESTRONG.COM and Trails. He often writes articles covering uncommon travel destinations from firsthand experience. Biscoe holds a Certificate of Completion in acting from the Pacific Conservatory of the Performing Arts.

Don't Miss a Thing!

All our latest outdoor content delivered to your inbox once a week.



We promise to keep your email address safe and secure.