How to flush fresh water tank?

[mlagrange56]

Hello - I live full-time in a Riverstone Reserve 3850RK, in a RV park in Houston, Texas.
I have let my fresh water tank sit 50% full for 6 months now. We are about to have a freeze tonight, and I would like to flush & re-fill it, so I can disconnect the fresh water hose, but still keep water into the rv for toilet flushing. (I will also fill up a couple of 5-gallon jugs for drinking water, just to be on the safe side.)
I've looked through the user manuals, but don't see anything about this. I also e-mailed Riverstone service yesterday morning, but have not received any response.
Anybody done this, on this model rv?
Thanks very much.

[W5CRE]

You have tank heaters. You do need water in the tanks for these heaters to be effective. If you can skirt the trailer at least where your tanks are it could help. Make sure and disconnect the water connection. I'd proceed with flushing and refilling the fresh water tank. Good luck. I'm in Galveston, (near Texas). South Houston will be safer than North Houston.

[mlagrange56]

Originally Posted by W5CRE

You have tank heaters. You do need water in the tanks for these heaters to be effective. If you can skirt the trailer at least where your tanks are it could help. Make sure and disconnect the water connection. I'd proceed with flushing and refilling the fresh water tank. Good luck. I'm in Galveston, (near Texas). South Houston will be safer than North Houston.

Right, I'm not worried about the tanks freezing, I just want to disconnect the
fresh water hose, and still have water in the rv.
I realize it might be a little late for cleaning the tank well enough to trust the water for drinking, but I would still like to be able to flush the toilet.
Have you seen the process for flushing the fresh water tank on this rv anywhere?

[Iwritecode]

This should get you started:

https://www.forestriverforums.com/fo...rchid=13856626

[NavyLCDR]

Personally, if it were me, to flush the fresh water tank I would open the fresh water tank valve and drain it until no more water was flowing from the drain. Then I would close the drain valve, and refill the freshwater tank. Is there some complexity to the situation I am seeing here?

Is it really necessary, though? My house has a 1700 gallon cistern that is filled from the well pump. It's got a level switch that cycles the well pump on at off at something like 60% to 100% full. That cistern has not been emptied and refilled for probably 20 years.

[D W]

Hmmmm, half full and sitting for 6 months? I would say that the FW tank and contents are questionable. Have you never flushed or sanitized the FW tank before?

[NavyLCDR]

Originally Posted by D W

Hmmmm, half full and sitting for 6 months? I would say that the FW tank and contents are questionable. Have you never flushed or sanitized the FW tank before?

Sources such as the CDC and USDA recommend replacing stored water every six months. So the drain and refill for drinking water is right at the recommended interval already.

Still, the question of "how to flush the tank". Well:

1. Drain the tank.
2. Refill the tank.

If you want to sanitize the tank in between then it becomes:

1. Drain the tank.
2. Refill the tank, add bleach while refilling.
3. Let it sit for at 4 hours with the bleach/water solution.
4. Drain the tank.
5. Refill the tank.

Again, unless I am missing some complexity associated with the situation.

[mlagrange56]

Originally Posted by Iwritecode

This should get you started:

https://www.forestriverforums.com/fo...rchid=13856626

WOW... Thanks very much!

[mlagrange56]

Originally Posted by NavyLCDR

Sources such as the CDC and USDA recommend replacing stored water every six months. So the drain and refill for drinking water is right at the recommended interval already.

Still, the question of "how to flush the tank". Well:

1. Drain the tank.
2. Refill the tank.

If you want to sanitize the tank in between then it becomes:

1. Drain the tank.
2. Refill the tank, add bleach while refilling.
3. Let it sit for at 4 hours with the bleach/water solution.
4. Drain the tank.
5. Refill the tank.

Again, unless I am missing some complexity associated with the situation.

Thanks, that helps. I thought there might be something special, given that there's a connection for flushing the black tank, and that 3-way water supply switch.

[NavyLCDR]

Originally Posted by mlagrange56

Thanks, that helps. I thought there might be something special, given that there's a connection for flushing the black tank, and that 3-way water supply switch.

My freshwater tank is currently drained for winterization. I have company coming in a couple weeks to spend 3 nights in the trailer. Thus, I am starting at step 2. I am going to:
1. Close the freshwater tank drain valve.
2. Pour 1/4 cup bleach into the end of my freshwater hose.
3. Flush the bleach from the hose into the freshwater tank while filling it.
4. Use my freshwater pump and pump water/bleach solution through all faucets, including the water heater (not turned on) and hot water faucets. My grey water tank drain is currently open, it's just going to drain onto my gravel driveway.
5. Once I get water/bleach solution through all the faucets, I'm going to leave the freshwater pump turned on and let everything sit for at least 4 hours (overnight for me).
6. Turn off the freshwater pump. Drain the freshwater tank and water heater.
7. Fill freshwater tank with water.
8. Turn on freshwater pump and pump freshwater again through all faucets, water heater, hot and cold faucets. Again, letting it all drain onto my gravel driveway.
9. Once I get freshwater through all the faucets, shut off all faucets, leave the water pump on, shut the grey water tank drain.
10. Top off the freshwater tank and store the freshwater hose.

A little note, you can use a simple swimming pool chlorine test strip or test-tube detection kit to determine when you get chlorine out of the faucets, and also when you have no chlorine during the final clean water steps.

Note 2, you will want to remove any charcoal filters from their canisters if you are going to sanitize. One of the main purposes of charcoal filter cartridges is to remove chlorine.

[Reverse_snowbird]

Originally Posted by mlagrange56

Hello - I live full-time in a Riverstone Reserve 3850RK, in a RV park in Houston, Texas.
I have let my fresh water tank sit 50% full for 6 months now. We are about to have a freeze tonight, and I would like to flush & re-fill it, so I can disconnect the fresh water hose, but still keep water into the rv for toilet flushing. (I will also fill up a couple of 5-gallon jugs for drinking water, just to be on the safe side.)
Thanks very much.

The rv park probably doesn't want you dumping fresh water onto their pad. The quick solution would be to put bleach into that fresh water tank to kill any bacteria in there and use that water to flush the toilet for the next day or so til you can disinfect the system. Probably keep the lid down on the toilet to be safe.

The safer way would be to blow water out of the lines with 30psi and leave the faucets and cabinet doors open and fill a couple of more jugs for flushing the toilet. Just put in water and step on the lever.

[NavyLCDR]

Upon re-reading everything....since you are at a full-time full hookup site (assuming). I think I would just open your grey water drain to the sewer hookup and turn on your water pump and kitchen faucets and pump your freshwater tank dry. Then close your grey water tank drain valve and faucets and refill your freshwater tank. You'll need to let your freshwater pump run for a few minutes with a faucet open to get it to prime itself again.

[The Newsoms]

If you’re not going to drink it, why drain it? Just fill it up. Get some drinking water and you’re good.

[Larry-NC]

Originally Posted by NavyLCDR

My freshwater tank is currently drained for winterization. I have company coming in a couple weeks to spend 3 nights in the trailer. Thus, I am starting at step 2. I am going to:
1. Close the freshwater tank drain valve.
2. Pour 1/4 cup bleach into the end of my freshwater hose.
3. Flush the bleach from the hose into the freshwater tank while filling it.
4. Use my freshwater pump and pump water/bleach solution through all faucets, including the water heater (not turned on) and hot water faucets. My grey water tank drain is currently open, it's just going to drain onto my gravel driveway.
5. Once I get water/bleach solution through all the faucets, I'm going to leave the freshwater pump turned on and let everything sit for at least 4 hours (overnight for me).
6. Turn off the freshwater pump. Drain the freshwater tank and water heater.
7. Fill freshwater tank with water.
8. Turn on freshwater pump and pump freshwater again through all faucets, water heater, hot and cold faucets. Again, letting it all drain onto my gravel driveway.
9. Once I get freshwater through all the faucets, shut off all faucets, leave the water pump on, shut the grey water tank drain.
10. Top off the freshwater tank and store the freshwater hose.

A little note, you can use a simple swimming pool chlorine test strip or test-tube detection kit to determine when you get chlorine out of the faucets, and also when you have no chlorine during the final clean water steps.

Note 2, you will want to remove any charcoal filters from their canisters if you are going to sanitize. One of the main purposes of charcoal filter cartridges is to remove chlorine.

Do not run bleach through an aluminum hot water heater!

If your water heater has an aluminum tank (like the Atwoods do), DO NOT run the bleach through it. It's okay to bypass the water heater to run the bleach solution through the hot water plumbing and taps.

Chlorine bleach goes through aluminum VERY QUICKLY. I ruined a couple of vacuum bottles by rinsing them with Clorox before I figured this out.

[Iwritecode]

Originally Posted by Larry-NC

Do not run bleach through an aluminum hot water heater!

If your water heater has an aluminum tank (like the Atwoods do), DO NOT run the bleach through it. It's okay to bypass the water heater to run the bleach solution through the hot water plumbing and taps.

Chlorine bleach goes through aluminum VERY QUICKLY. I ruined a couple of vacuum bottles by rinsing them with Clorox before I figured this out.

I can't find any sources confirming this anywhere.

I believe it would be perfectly safe. Especially diluted to the levels normally used in sanitizing freshwater tanks. Even if you poured straight bleach in the most it might do is change the color of the metal.

[mlagrange56]

Thank you all for your responses. I appreciate the all the detail; now I need to get this done before the next big freeze.

[NavyLCDR]

I underestimated the amount of bleach you want to use. This website suggests 1 cup for 40 gallons:
https://www.sanidumps.com/sanitizerv...atersystem.php

The same website has these steps:

11. If you have a bypass for your hot water tank, make sure that is set for normal use so that the bleached mixture will be pumped through the hot water tank.
12. Top up the fresh water tank with water.
13. Run the chlorinated water through all lines (hot and cold one at a time) for one or two minutes, you should be able to smell the chlorine.

This website also says to make sure to fill the water heater too to sanitize it:
https://koa.com/blog/how-to-sanitize...ntenance-tips/

Use the gallon jug and funnel to add bleach and water until the freshwater tank is almost full
Turn the water pump on and open a hot water faucet to fill the water heater
When the water heater tank is full, open all hot and cold faucets one at a time and run the water until you smell bleach at each faucet

If you have an on-demand water heater with a copper heat exchanger, then you don't want to run chlorine through it. That warning will be in your water heater manual.

Also first step at this website:
https://www.rvtravel.com/rv-fresh-water-chlorination/

1. Drain and flush the fresh water tank; leave empty. Be sure the water heater is not in the bypass mode.

[dalford]

Originally Posted by The Newsoms

If you’re not going to drink it, why drain it? Just fill it up. Get some drinking water and you’re good.

X2^^^^^

[Tom48]

Originally Posted by Iwritecode

This should get you started:

https://www.forestriverforums.com/fo...rchid=13856626

bad link!

[MNtraveler]

Originally Posted by The Newsoms

If you’re not going to drink it, why drain it? Just fill it up. Get some drinking water and you’re good.

Agreed! If you aren’t going to drink it, there’s no need to flush or bleach it. Just use as is. Get drinking water. You can also boil the water for 3 minutes and use it for anything.