ronheb454 Report post Posted August 15, 2018 I have a 2015 Thor Miramar with a bath and a half. The half bath toilet clogs up often. I checked the vent pipe which appears open. The Thor diagram shows the toilet has two 45 degree bends going to the tank which doesn't seem like much. Sometimes I have to plunge this toilet. I have seen this toilet fill with water while holding the lever open than all of a sudden it runs done and works fine. Does anybody have an idea of what I might be missing or what I could try. This black tank empties out fine. I usually run some water into the tank after I emptied it and it seems like the amount I just put in the tank. Thanks much for your time. Share this post Link to post Share on other sites
hermanmullins Report post Posted August 15, 2018 Ron, There seems to be some sort of obstruction as you are aware of. It may take a camera out down to see what is causing the obstruction. Is the half bath in the middle or in the rear? I have heard more than once that the rear toilet takes a lot of water to flush due to the distance it has to travel. Herman Share this post Link to post Share on other sites
ronheb454 Report post Posted August 15, 2018 I was thinking about a camera, this half bath is in the middle of the coach. Share this post Link to post Share on other sites
wildebill308 Report post Posted August 15, 2018 Like Herman I would try a little more water. Bill Share this post Link to post Share on other sites
obedb Report post Posted August 16, 2018 My guess is and it is only a guess, that the toilet that is most distant from the black water holding tank is the culprit. If that is the case, and you don't entertain a lot, use the offending tank for urine only and have the misses use a small trash can for the tissue. Have no experience with a bath and one half, but we do live in a rural setting with a septic tank and therefore try to take it easy with unnecessary things heading to the tank. Betty uses a bathroom trash can with a lid when possible. Share this post Link to post Share on other sites
ronheb454 Report post Posted August 16, 2018 I don't believe the black tank is far from the toilet. Usually when it clogs it doesn't take much to plunge it free. I know what you are saying about using the main rear toilet, it just bugs me because that is why we purchased a bath and a half. Like I said, it is crazy I watched it fill up then all of a sudden drain down and work fine. I know there are a lot of coaches out there now with a bath and a half and now some have two full baths. Share this post Link to post Share on other sites
Chrisk22 Report post Posted August 16, 2018 i Think herman is on to this Share this post Link to post Share on other sites
wayne77590 Report post Posted August 16, 2018 I just have to ask. Are you using RV(septic) safe toilet tissue? Also no Kleenex type tissues in the toilet? You may know this already but if you take a square of toilet tissue and drop it into a glass of water it should break up and sort of dissolve to nothing. Share this post Link to post Share on other sites
ronheb454 Report post Posted August 17, 2018 Yes Sir, I am using RV specific toilet paper. I have a septic tank at my residence for over 40 years so I am very familiar with the toilet paper issue. My problem is not with the paper, I believe it is really a vent issue. I was curious if anyone else with a bath and a half had issues with their middle half bath toilet. It is hard for me to believe that the only way to not have a problem with it is to limit the use. There would really be no point in having the second toilet then. I know there were a lot of coaches sold with half baths. I guess I am the unlucky one that has an issue. I will keep digging and hopefully find the cure. Share this post Link to post Share on other sites
desertdeals69 Report post Posted August 17, 2018 Its my understanding that rv toilets are designed to be mounted over the black tank with a straight shot down. Any bends will create resistance. We have serviced some trailers with plumbing that has bends and the owners experienced some problems. The cure seemed to be to flush more often with a smaller load. Share this post Link to post Share on other sites
kaypsmith Report post Posted August 17, 2018 Where is the black tank in reference to the toilet? Have you climbed onto the roof and checked the vent for any obstructions? You can remove the vent cover and place a hose pipe attached to a fresh water supply and force water down the vent, the water will go directly to the holding tank, and this is the only way to clean the vent pipe that I know of. I personally have never liked having any type elbow in the toilet drain to the black tank. Page 110 of your manual does reference using plenty water while flushing the toilet to avoid conditions just like you described. I am unable to find plumbing diagrams of your coach, but I suspect the main toilet uses a power flush system. I will add one suggestion, acquire some Calgon water softener, Walmart and other box stores sell it, located where detergents are sold, use a quarter cup in a two gallon container, add one quarter cup of Dawn dish detergent, fill the container with hot water, then while holding the flush valve wide open, slowly pour the solution down the affected toilet. If an accumulation has begun to build up in those elbows, this will help to loosen and force down into the black tank. This is also a most effective means of cleaning the black tank. DD69 beat me to part of my response while I was typing, but what he said is very true. Share this post Link to post Share on other sites
rsbilledwards Report post Posted August 17, 2018 DD is a load really controllable or do you split it up???? Share this post Link to post Share on other sites
wajames Report post Posted August 17, 2018 All good advice. We had an issue where the inlet pipe was inserted too far and was close to the "step" in the black tank, I kept a coat hanger nearby to poke it if stuff/paper clogged up. On ours, the inlet tube slides down into a sealing collar on the tank top which is then sealed with silicone - so an over-eager installer can leave too much pipe in the tank. We had an unrelated tank failure and the new tank had the inlet hole away from the "step". Our inlet has 2 45 degree bends, but otherwise it is right over the tank and we've had no clogs since (well once when too much paper and not enough water was used). That could explain why no one else has the issue. Herman's advice on a camera would be the way to tell. Some of the RV flush services have cameras. Share this post Link to post Share on other sites
ronheb454 Report post Posted August 17, 2018 Hey thanks much guys. As stated my Thor diagram shows (2) 45 degree elbows going to the black tank. I didn't think this was much but maybe it does create a problem. I will run water down the vent tube as the diagram shows it is connected to the back of the 3 inch offset flange. I should be able to see water running in with the toilet flapper open. I will also try mixing up the Calgon solution and see how that works. Thanks for the suggestion's everyone. Share this post Link to post Share on other sites