How to remove water from gray tank??

[huck55]

I am preparing to winterize my 2019 25’ FC.

There are instructions to blow out the blank tank, the fresh water tank, and all the faucets, but no instructions or procedures to remove water from gray tank.

Is there a way to remove water from the gray tank?

[ROBERT CROSS]

Well, actually it should be empty after your last outing...
If not...you could MacGyver a cap like this, connect a garden hose and empty into the storm sewer.

POI 3-gal or so hasn't damaged our tank, if worried pour a gal of AF down the kitchen sink.

Bob
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[Dennis C]

I use the dump station to do this after I winterize.

[Castaway]

As long as the air in the tank can vent, pressure will not build up causing expansion . Its not the frozen water that causes cracks , its the built up air pressure. To prove this put 2 completely full bottles of water in the freezer leaving the cap off of 1 of them and the other cap as tight as you can twist it, the 1 without the lid will not crack but the water will swell up and out of the opening. Remember that water expands when it freezes.

[AstroBruce]

Originally Posted by Castaway

As long as the air in the tank can vent, pressure will not build up causing expansion . Its not the frozen water that causes cracks , its the built up air pressure. To prove this put 2 completely full bottles of water in the freezer leaving the cap off of 1 of them and the other cap as tight as you can twist it, the 1 without the lid will not crack but the water will swell up and out of the opening. Remember that water expands when it freezes.

I'm not buying this at all. If what you're saying were true, there would be no need to winterize the fresh water system. Just leave the faucets open to relieve the pressure. We all know that won't prevent cracked plumbing.

Bruce

[richard5933]

Originally Posted by AstroBruce

I'm not buying this at all. If what you're saying were true, there would be no need to winterize the fresh water system. Just leave the faucets open to relieve the pressure. We all know that won't prevent cracked plumbing.



Bruce

I think that you're spot on.

A small amount of residual water left in the bottom of the tank or the bottom of a water heater is unlikely to case issues, but it's the size and shape of the tank relative to the small volume of water. Venting had nothing to do with it.

[s1000pre]

Just empty the tank as usual. Then winterize, the antifreeze running through the faucets and into the drains will protect from any residual left in the tank. As already noted, I always pour a good quart or so into every drain even after running the antifreeze through the pipes

[Wazbro]

The black tank has a flush line that needs to be blown out, really nothing to do with blowing out the tank. The tank just gets drained like normal dump.
Gray tank has no flush system so just gets dumped like normal use.
You do need to make sure there is RV anti-freeze in the traps; both sinks and shower..

[richard5933]

Originally Posted by Wazbro

The black tank has a flush line that needs to be blown out, really nothing to do with blowing out the tank. The tank just gets drained like normal dump.
Gray tank has no flush system so just gets dumped like normal use.
You do need to make sure there is RV anti-freeze in the traps; both sinks and shower..

What's generally done once that black tank flush becomes blocked, like happens to so many trailers over the years? Mine won't let anything through - not water and not antifreeze. I've got to hope that means there is no water in there to freeze. But even so, if there is, what would be damaged other than the black tank flush?

[Wazbro]

Originally Posted by richard5933

What's generally done once that black tank flush becomes blocked, like happens to so many trailers over the years? Mine won't let anything through - not water and not antifreeze. I've got to hope that means there is no water in there to freeze. But even so, if there is, what would be damaged other than the black tank flush?

It would only damage the black tank flush.

[Silvr_Bullet]

Blow air through the Black Water Flush connector. I use a CAMCO hand pump to run some RV antifreeze through the same fitting.

[Castaway]

Originally Posted by AstroBruce

I'm not buying this at all. If what you're saying were true, there would be no need to winterize the fresh water system. Just leave the faucets open to relieve the pressure. We all know that won't prevent cracked plumbing.

Bruce

Try the water bottles and see what happens. You will still need to blow with air so that the pump and the toilet valve are clear of water. These 2 things hold the water in without an air release. Freezing water follows the path of least resistance so if the air has room to escape water will replace its space, if the air cannot escape the water will try expanding and the trapped air will sometimes provide more resistance than the surrounding material.

[psy1]

After your final gray tank dump prior to winterization, there will be a small amount of residual water in the gray tank. There is no way to blow that out. Whether you use compressed air or all antifreeze method to winterize, you will still be dumping antifreeze into the sinks and shower drain to protect the P-traps from freezing. Just make sure you add plenty so that some drains into the gray tank and you should be fine.

[drbrick]

We use both the "blow-out" and "antifreeze" - we place antifreeze in both the Black and Grey tanks ( about 2cups ) + the amount which flows into them when we antifreeze the waterlines. We antifreeze to protect the water pump. ( Don't forget to drain the hotwater tank and turn on the by-pass. ) Basically the way the B&G tanks are install "should" allow the liquid" to flow towards the gate valves thus protecting the seals. As far as the fresh water tank goes once drained leave the valves open so any residual water won't go there and freeze. WHATEVER YOU DO - DO NOT PUT ANTIFREEZE IN THE FRESH WATER TANK... sorry for shouting, if you do you will never get the taste of antifreeze out of the tank

[Keith S]

POI I remove the garden hoses from the faucets and then turn off the water to the faucets in the basement. Then open the faucets.
I leave the garden hoses coiled up on the wall through the winter. No problem
We don’t completely empty our grey tanks other than drain them at a dump station and pour some antifreeze into all the drains.
Regards,
Keith S

[Fungus]

3 degrees F last winter here.

Empty the three tanks. Blow the lines. Pour the pink stuff in the traps and a half gallon in the toilet, plus a little extra for the elves in the gray tank. I did not blow the black tank’s sprayers but it can’t hurt and takes only a minute.

[ROBERT CROSS]

Originally Posted by psy1

After your final gray tank dump prior to winterization, there will be a small amount of residual water in the gray tank. There is no way to blow that out. Whether you use compressed air or all antifreeze method to winterize, you will still be dumping antifreeze into the sinks and shower drain to protect the P-traps from freezing. Just make sure you add plenty so that some drains into the gray tank and you should be fine.

Not just the grey & black tanks, include the FW tank.

Three yrs ago, I drained all the tanks...the following day I raised the streetside with the FW valve still open, it drained for close to 1/2hr.
I haven't put AF in the FW tank in over 10yrs. I'm sure some of that water has frozen in the past...never caused a leak.
I don't believe frozen water in the tanks is as serious as folks think.
We'd be replacing a LOT more tanks if it was.

Bob
🇺🇸

[Wazbro]

Originally Posted by ROBERT CROSS

Not just the grey & black tanks, include the FW tank.

Three yrs ago, I drained all the tanks...the following day I raised the streetside with the FW valve still open, it drained for close to 1/2hr.
I haven't put AF in the FW tank in over 10yrs. I'm sure some of that water has frozen in the past...never caused a leak.
I don't believe frozen water in the tanks is as serious as folks think.
We'd be replacing a LOT more tanks if it was.

Bob
����

I believe your right that frozen water in the tanks is as serious as folks think as long as there isn't much in them. I've made a few trips going south winterized camping and just used jugs of water to flush the toilet till getting south of the freeze line with no problems. I would use RV anti-freeze to flush while coming north after winterizing though just to make sure I could dump when I got home.

[richard5933]

Originally Posted by ROBERT CROSS

...
I don't believe frozen water in the tanks is as serious as folks think.
We'd be replacing a LOT more tanks if it was.

Bob
🇺🇸

All depends on how much water is in the tanks. The manual talks about there being some residual water and that it won't cause a problem. As long as people drain what's possible through normal methods they should be okay. Leave a few inches of liquid in there and all bets are off.

[ROBERT CROSS]

Originally Posted by richard5933

All depends on how much water is in the tanks. The manual talks about there being some residual water and that it won't cause a problem. As long as people drain what's possible through normal methods they should be okay. Leave a few inches of liquid in there and all bets are off.

I can't say how many gallons a couple inches is, but after lifting the streetside, It started again and continued for about half an hour.

Bob
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