Black Tank draining issues

[LADerouen]

I purchased my Reflection new in 2016 and have issues with the tanks draining completely. There are times when they wont drain at all. I have been told that it is possible they dropped the plug when they cut in the floor for the toilet could be stopping it from draining. Would apricate some help on tis matter on what should i do next. I've had it at the dealer and they said they found nothing. we do not put any paper in there and always use the chemicals that's required. I have gone a far as driving down the dirt road and switching left to right to get the water out. please give my some advise. we love our trailer but can use the toilet.
Thanks
Lloyd

 

[Knightclimber]

Find someone with a scope to check the lines. Many plumbers have them but that can be an expensive option.

 

[jkwilson]

You can buy an endoscope camera for your phone for less than $50. It’s a very handy tool.

 

[Knightclimber]

You can buy an endoscope camera for your phone for less than $50. It’s a very handy tool.

True, but make sure if you get one that the light is very good on it and it is long enough to reach all the way to the tanks. The one I have, the light is barely serviceable for looking at anything more than an inch away.