This is Why You Descale a Tankless RV Water Heater (& How To Do It Correctly), by RV Tips & Travels on YouTube. 6 min 3 s.
- Video length
- 6 min 3 s
- Time to do it
- 1 hour
- Difficulty
- Easy
- Steps
- 8
What you need
Steps
Turn the water heater off and let it cool completely. Shut off the water supply to the rig and disconnect power or gas to the heater before you touch anything.
Close the isolation valves on the heater so water stops flowing through it, then remove the caps from the hot and cold service ports.
Wrap Teflon tape around the threads of each service port and screw in the GHT to NPT adapters. Hand tighten them, then a quarter turn with a wrench.
Pour about a gallon of white vinegar into the 5 gallon bucket. Dilute it only if your heater or kit manual tells you to.
Drop the pump's intake hose into the bucket. Connect the pump outlet to the cold service port and run the return hose from the hot port back into the bucket.
Plug in the pump and let the vinegar circulate through the heater for 30 to 45 minutes. Check the hose fittings once or twice for drips.
Switch the pump off, move the intake hose to a bucket of clean water, and circulate fresh water for a few minutes to rinse the vinegar out.
Remove the adapters and hoses, refit the service port caps, and reopen the isolation valves. Turn the water and power back on and run a hot tap to check for leaks.
Tips and common mistakes
Never let the pump run dry, since it will suck air and stop moving the vinegar through the heater.
Skip cider or malt vinegar and use plain white vinegar, which rinses clean and leaves no smell.
Descale at least once a year, and more often if you camp where the water is hard.
If hot water flow or temperature has already dropped, the scale has been building for a while, so do not put the job off.
Questions
How often should I descale a tankless RV water heater?
Most owners do it once a year as routine maintenance. If you often use hard water, plan on every six months.
Can I use a commercial descaler instead of vinegar?
Yes. Follow the mixing ratio on the bottle and rinse the heater just as thoroughly afterwards.
Do I need to remove the heater to do this?
No. The service ports let you circulate the vinegar through the unit while it stays in place.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
