201QB tank sizes

[bkenobi69@yahoo.com]

The tank is secured to the frame with long steel cross-members it appears. The floor is right above the tank. The pipes are punched through the floor and solidly glued at every connection. The vent/kitchen sink drain are inside a wall basically inside the bathroom door frame. I can see and touch it from the bathroom cabinet access but its around a bend with things in the way (black tank vent line, framing, etc). The other inlet is under the dinette and easily seen. That connection is a 90 bend right into the floor so no way to do anything there either.

The only way i see of freeing things is if there is abs glue softener of some kind. I thought abs bonded and wasn't glued though. I might be able to cut but once i do that its a serious commitment if i have to pull the tank as a worst case!

[franktafl]

https://www.youtube.com/watch?v=rfO9WkHiS5c

[franktafl]

https://www.youtube.com/watch?v=zYJCLzGaaB8

He gives actual formulas to figure out the capacity…

[bkenobi69@yahoo.com]

I'm going to pull the black plastic on the bottom down a bit more so I can get a good measurement and see if there is anything that might help. I don't think it will matter, but at least I'll know how things are situated a little better. The issue is that the interior of the trailer is not configured so I can access the plumbing for the vent and the other side is glued into the floor. I could potentially cut the fitting and remove it from the vertical pipe that goes into the tank, but I'm not sure if that would help. On the up side, I could possibly use a rotary cutter of some kind to shorten the pipe inside the tank (though it would be VERY rough). I could not easily do anything on the other side though so not sure it's worth that effort.


I'm tempted to just accept it as a 20 gallon gray tank for now but that doesn't sit well.

[bkenobi69@yahoo.com]

After watching the videos you posted, I continued looking on other similar videos. From what I'm seeing, the vent in the top of the tank typically has a fitting that attaches to the top of the tank. I guess the 1-1/2" pipe is then inserted and glued into that. If I understand, the short pipe that they installed must have been pushed through the fitting such that it's well within the tank rather than effectively flush with the top?


The videos I've seen suggest that the only way to access that vent fitting is by removing the tank. To do that, since everything is glued together on my trailer, I'd have to cut things out so the tank can be freed and then rebuild as needed. If I had ready/working access to the inlets, that doesn't sound too bad. Dropping the tank doesn't look all that fun, but since I really don't see how to get to the vent/kitchen sink pipe that seems pretty problematic!

[persistent]

"I guess the 1-1/2" pipe is then inserted and glued into that. If I understand, the short pipe that they installed must have been pushed through the fitting such that it's well within the tank rather than effectively flush with the top?"

There are different types of fittings for the top of a tank. Best advice would be from a dealer service center or the RV manufacturer.

Typically the tank has a threaded fitting. As in the video, it may be inside the tank wall or it may be on top of the tank wall. The 1 1/2 inch pipe has a glued on threaded fitting that mates with the threaded tank fitting.

This type of fitting set usually would not allow the pipe to pass through into the tank.

Another type of fitting is a compression seal fitting. These are often used in sink p trap installations. It allows the pipe to pass through the tank wall so you don't have to have an exact length.

Since you say it looks glued, then it is probably not a compression seal fitting. The end of the pipe is probably glued to a threaded fitting.

It is possible to have a fitting glued to the tank and the pipe glued to that fitting. It is unlikely the pipe is glued directly to the tank wall.

If so, cut the pipe a few inches above the existing glue joint. Later insert a joiner system, either glue or threaded union.

You may be able to remove wall panel inside the RV to access plumbing from the top. That may be how it was installed at the factory.

This is where an experiences RV plumber's knowledge and experience come in handy. I am not an RV plumber.

[bkenobi69@yahoo.com]

Just to be clear, from the plumbing I can see, everything is neatly glued together. The only thing not glued are the p-traps for the sinks and shower. It is possible the connection to the tanks are done another way but when talking to Keystone it sounded like they typically glue those fittings.

I can talk to the dealer's service guys again to see what they would recommend at this point.

[bkenobi69@yahoo.com]

I stopped by the dealer again this week to talk to the tech. He said that while the manufacturers do glue or screw the vent tubes into the tank sometimes, his experience with this model of trailer (the Kodiak UL of this size) is that they are always a 39 gallon tank with a rubber adapter inserted after the tank is drilled. Basically they put the tank in place, drill a hole where the tube is needed, pull it back down, and install the rubber adapter. They add a tube to the adapter that is too long so that when it is put back into place, they cut to the correct length. He is guessing that when it was raised back into place, the stub on the vent (at least) was pushed past the stop on the rubber adapter and then cut/glued in the tube run. So now the tube is too deep as I have seen.


The options he suggested were:

1. Cut the vent and kitchen pipes in a convenient location in a straight section. With those pipe runs free, pull the existing y-portion out of the tank. Mark and cut to the correct length. Reinsert using the wax from a toilet ring as lubricant and sealant. Use rubber couplers to reattach the vent and kitchen pipes.
2. Remove the drain pipe on the bottom of the tank. Reach through with a compact saw to cut the stub inside the tank shorter. Reinstall drain pipe.
3. Leave as is and only have a 20 gallon tank.
4. Bring it to them and they can fix it. No estimate for time to repair given but at $200/hr I imagine that could be a $1000 repair pretty quickly.

[bkenobi69@yahoo.com]

I decided to cut the drain line from the bathroom into the tank so I could see if the inlet would come out or if it was glued/threaded and also have the ability to put the boroscope into the tank and be able to navigate around.


Before pulling the stub out, I added water 1 gallon at a time again to make sure the Fernco coupling was water tight. I did twist on it a little and found it had some resistance that would require a strap wrench of some kind which may have broken the seal to the tank. When I got to 21 gallons, the sensor read full but this time it didn't back up into the shower. I added a few more gallons and still no issue. I believe this confirms that the vent pipe was the issue with water backing up, so I will have to reseal the bathroom inlet so it's not venting into the trailer.


I then used the boroscope by the tank dump side (the propane line is keeping me from being able to pull down the plastic underbelly). It shows pretty clearly that the other suspicion was true. The sensors are installed such that 1/2 and 2/3 (yellow and green wires) are on the vertical surface of the tank and spaced evenly. The full sensor (red wire) is on the horizontal ledge above the dump port which means that full will be approximately 2/3 full. If I want to fix that, I'll have to pull the underbelly down, drill a new hole in an appropriate spot, and move the wire to a new sensor installation. Doesn't sound too hard to do other than having to remove the propane line.


On the up side, I know what the issues are and how to fix them. On the down side, it's kind of a pain in the arse to fix them. If I do go that route, I'll go ahead and install tank heaters and insulation at the same time since I'll already have the underbelly off.

[bkenobi69@yahoo.com]

After talking to the dealer again and doing more digging in the hole in the floor, I realized that the vertical drain tube was sealed into the rubber grommet using butyl tape for some reason. Before attempting to remove, I ran my boroscope down the hole and angled it up at the inside which confirmed that the tube was about 2" past the grommet's end. I couldn't get the camera to cooperate and reach the other end of the tank where the vent was so I got to work pulling the rest of the bathroom pipe out.



The grommet was spinning but the pipe wouldn't budge. After some persuasion with a screw driver I was able to get the pipe to break loose. Butyl tape is a great seal choice IMO but it's supper messy to mock up the proper length to cut off so I cleaned it up with mineral spirits and a putty knife. I haven't sealed it back up yet in case I need to access before I finish up.


As for the vent pipe, I think the best option is to create an access panel next to the furnace inside the bottom of the pantry. I'm surprised that wasn't an access already so it will look fine. It's also hidden by the pantry door when shut. That will give me access directly to the vent pipe so between that and the bathroom access, I should be able to get to the pipe relatively easily.


I'm leaning towards dropping the propane supply so I can pull the basement sheet off and add tank heaters. The fresh water is below the floor so that one would make a big difference. The gray and black are less of an issue because I can and will add antifreeze to them. And with the corrugated down on the dump side I should have easy access to drill a small hole for the wires if needed.


Is the silver bubble wrap actually effective at insulating the basement any better? The R-value is only around 1 so I'm not sure it would even make a difference. My other thought was to use 1" XPS where the tanks aren't located and probably a sheet of the silver bubble wrap under the tanks just so the heaters mostly reflect up.

[persistent]

...

I'm leaning towards dropping the propane supply so I can pull the basement sheet off and add tank heaters. The fresh water is below the floor so that one would make a big difference. The gray and black are less of an issue because I can and will add antifreeze to them. And with the corrugated down on the dump side I should have easy access to drill a small hole for the wires if needed.

Is the silver bubble wrap actually effective at insulating the basement any better? The R-value is only around 1 so I'm not sure it would even make a difference. My other thought was to use 1" XPS where the tanks aren't located and probably a sheet of the silver bubble wrap under the tanks just so the heaters mostly reflect up.

I work with the dealer to do something similar to my Kodiak Cub. We used rigid foam board to reduce the size of the belly space to just big enough to include all the plumbing. We used paper sided fiberglass bats on the bottom side. It compresses a lot when the corrugated plastic is replaced.

Sealing cracks is very important. The frame to floor in mine was not sealed. A 60 mph wind tended to just blow all the heat away. Sealing the corrugated plastic to the frame is also important. Sealing all the outside holes is vital.

Follow instructions included with the heaters for installing tank heaters. The 120 volt supply can be connected to the air conditioning circuit breaker. You won't be using air conditioning at the same time as the A/C.

While the belly cover is off, you may wish to do the following:

1) Insulate all the pipes using pipe wrap or pipe insulation tubing. They will freeze first.

Also, the hot will cool off fast. Insulating it will reduce the amount of flushing water needed to bring the temp up at the faucet.

2) Bundle the helter skelter wiring and protect it where it rubs on frame edges.

3) Wrap the drain pipes with sturdy insulation. They will freeze and prevent dumping.

I thought I could use anti-freeze in the tanks. That did not work.

Automotive anti-freeze can be diluted with waste. However, Automotive anti-freeze has hazardous chemicals in it. It is not safe and may damage your tanks and valves.

RV anti-freeze cannot be diluted. RV anti-freeze only works full strength. Also, it does not keep the fluid liquid. It does freeze, it just does not expand and burst plumbing like water does.

Note: Make sure the furnace heat duct to the floor actually passes through the floor. Mine was only drilled half way through. No furnace heat passed through.

[bkenobi69@yahoo.com]

I was recommended fiberglass style insulation but I'm concerned about water and then mold (especially with pepper backing). Closed cell XPS can float on water and effectively is not affected by it. The problem with it is flexibility. The corrugated plastic sags a bit so there would be gaps everywhere.