I have discovered some of the drain valves on my Coachmen are defective. I can turn the plastic handles but not all the valves open.
Even though these handles show the valves are open two are still closed
If I remove the handle to confirm. So far FR doesn't appear to care as I was 23 days past the 1 year warranty when I discovered the defective valves.
I write a blog on RV tire application and safety. RVTireSafety.com
Also give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV