More Winter Fun, Draining Black Tank

[Nuffsaid]

After having our 310GK in Belgrade, MT for two weeks, we just got it home tonight. The entire time the trailer was up in MT we had all of the tank heaters on and kept the furnace around 70 degrees. I went to drain the black tank when we got home tonight and nothing came out. We poured some hot water down the toilet and it came out of the hose. My tank shows full, but I am not sure. I would have hooked up a hose to the black flush, but it was dark out and my frost free hydrant is frozen. I will try again tomorrow. Heat is still on. Now I am questioning whether the tank heater is working or not. The black tank valve moves open to closed without any problem.

[Paul & Deb]

Did you feel you were able to get it completely drained before you left it? I never, ever trust the tank level readouts. It only takes the slightest bit of material on the probes to give a false reading.

[Nuffsaid]

Did you feel you were able to get it completely drained before you left it? I never, ever trust the tank level readouts. It only takes the slightest bit of material on the probes to give a false reading.

The valve on the black tank was closed for two weeks, so it should be full. I am just wondering if it is a full ice cube! This would be the first test of the tank heaters and it appears that it might not be working. I am going to pull the trailer into a heated shop tomorrow and let it thaw out, then I will know.

[Cate&Rob]

The valve on the black tank was closed for two weeks, so it should be full. I am just wondering if it is a full ice cube! This would be the first test of the tank heaters and it appears that it might not be working. I am going to pull the trailer into a heated shop tomorrow and let it thaw out, then I will know.

The only way to really know if your tank heaters are working, is to monitor current draw either on just that wire or with everything else turned off.

Rob

[Nuffsaid]

I pulled the trailer into a heated shop at work this morning and when I pulled the sewer cover off, there was some liquid from the black tank. The pipe was totally clear the other evening when I checked it, but there must have been some residual frozen material above where I could see. The trailer has been parked outside at my house with the heater on and tank heaters on also. I will take the trailer back home in a little while and try to drain the tank again. It is cold out today, only 16 degrees at 1:30 pm, but I need to get this done because we are supposed to get hammered with a storm Sunday and have teens below zero on Monday. I will update again.

[Cate&Rob]

Since this is the black tank that you are dealing with, you could feed a 120V heating cable (such as used to prevent eavestrough freeze up) down the toilet and leave it plugged in until you are confident that the tank contents are not frozen.

Rob

[Nuffsaid]

Since this is the black tank that you are dealing with, you could feed a 120V heating cable (such as used to prevent eavestrough freeze up) down the toilet and leave it plugged in until you are confident that the tank contents are not frozen.

Rob

Good idea Rob, but I got it drained, contents were kind of slushy, but tank heaters must be working. Maybe the problem is that cold air goes up the sewer pipe and creates an ice jam of sorts.
It seems that between the heater running and the tank heater, the tank was already thawing from sitting the last two days. It is possible that while driving in cold sub freezing weather the contents got super cooled. Anyway, contents came out in spurts and I added fresh water to flush, doesn't melt real good when the fresh water is about 35 degrees, LOL. Blew out all the water lines with air and trailer is ready for the next adventure, probably heading to CA in a couple of weeks to see my dad.

[D2Reid]

Maybe the problem is that cold air goes up the sewer pipe and creates an ice jam of sorts.

It doesn't hurt to drop a gallon or two of pink stuff in the tanks when you are traveling in sub-20 weather. I have a last resort gate valve on the exterior connection of the drain pipe. I have learned that even when the internal tank valves are closed there may be a little seep, this seep collects and blocks the main pipe, you get poopcycle. I put a different end cap on, it has a standard garden hose connection that I leave open. The little bit of seep doesn't cause a grave environmental concern, but letting it drain out saves you from hours of de-icing the sewer system.

The full tank indicators are notoriously wrong.

[Nuffsaid]

I have a cap with a garden hose adapter also, but in cold climates like mine, the 3/4 inch hold gets blocked with ice pretty easy. A hot shower usually opens it back up though.

[howson]

It doesn't hurt to drop a gallon or two of pink stuff in the tanks when you are traveling in sub-20 weather.

Wow--answers like this make me want to slap my forehead. So simple and obvious to put antifreeze in the black tank but easily overlooked while (overthinkers like me) search for "the answer".

If Fran and I ever travel in cold weather I'll need to remember this one. Thanks for posting!