How to use all water in hot water tank and cold water tank? (Scamp)

[Scamperino]

New scamp owner here. I just got a 2016 13ft scamp. It has a 6 gallon hot water heater and a DC demand water pump. No hand pump.

While familiarizing myself with the setup I noticed that when you use the hot water tap, the 6G tank is always back filled from the 12G cold tank.

I will be boondocking the majority of the time, so I was thinking that it would be nice to have 18G of water on-board (12 in cold water tank, 6G in water heater). However, once the cold water tank is empty, it doesn't seem possible to get water from the hot water tank. This effectively limits me to carrying 12G of usable water and 6G of inaccessible dead weight.

To make maters worse, if I happen to actually use the water heater, now 1/2 my usable water is scorching hot and not great for drinking.

I can only see 1 valve in the hot water compartment that isolates the hot water tank from the cold supply, but this simply leaves me with 12G cold water and wasted cargo space.

Is this the typical operation of the hot water heater? Is there a way to access all 18G of water on-board or to isolate the hot water tank from the cold-water tank and only draw from the hot tank when the hot tap is used?

[Darwin Maring]

If you were to totally empty the hot water tank it could be ruined by it heating nothing but air in the tank if you were to forget to turn it off.

When in a camping ground, connect to their water supply.

[AlanKilian]

I don't have a water heater i my Scamp, but knowing a little about plumbing and water heaters in general (a little knowledge is a dangerous thing right?) I don't think you every want to let your hot water heater get less then completely full.

A water heater that isn't completely full can easily be damaged when the heat comes on.

That's likely why the plumbing is as it is, there's no way to run the tank partially-full since you need to add water to the inlet to get water to come out.

So, you'll always have 6 gallons in the heater unless you use one of the drain valves.

[Scamperino]

Thanks everyone. It makes sense that automatic filling is a kind of safety feature. I guess I will just count on having 12 gallons available and bring some extra water along in containers.

This is my first RV and when I first got it, I was flipping switches and turned on the water heater with no water in it and it ran for probably an hour empty before I realized that that switch wasnt for the furnace. I haven't noticed any leaks so far and after filing it with water, the heater seems to work fine... I hope I didn't break anything

[LarryB.]

Looking at your original entry, I presume that your objective is to have access to 18 gallons of water and that you're not interested in having hot water.

The answer is that it can't be done because you have one water pump that pressurizes both the hot and cold water lines. The water in the hot water tank is fed by the pump using the 12 gallon tank as a source. Once the 12 gallon tank is used the pump cannot pressurize the 6 gallons of water in the hot water tank.

Think of it this way, at home, if you have a 50(?) gallon hot water tank and the water company turns off your service, you can't get water from the hot water tank. Of course, you could open the drain plug and let the water flow into a bucket but you can't get that water at your sinks/bath....

If you are boondocking and you use alll the water in your 12 gallon tank, in an emergency you could remove the heating element from the hot water tank into a busket. However, as others have pointed out, be **VERY** careful that you shut off the energy source to your hot water tank.

[Mike_L]

I believe all hot water tanks work that way. The only other way to get the remaining water out of the hot water tank is through the drain valve.

[Radar1]

There is one way to do it as long as you don't plan to use any hot water.
After the fresh tank runs dry, just pull the drain plug or anode rod from the hot water tank and drain that 6 gallons of water. You could even drain it into a jug, and then pour it back into your fresh water tank. As long as you turn the heater bypass to off, those 6 gallons will be available from the cold tap.
Only problem is that before you ever turn that hot water tank on again, you need to put 6 gallons back in.

[Iowa Dave]

Here you go
A little piece of clear plastic hose slipped over the end of the petcock and you’re good to go after you reduce the pressure and cool the water if you’ve heated it up
Iowa Dave

Google: RV Anode with petcock

[computerspook]

Originally Posted by Scamperino

New scamp owner here. I just got a 2016 13ft scamp. It has a 6 gallon hot water heater and a DC demand water pump. No hand pump.

While familiarizing myself with the setup I noticed that when you use the hot water tap, the 6G tank is always back filled from the 12G cold tank.

I will be boondocking the majority of the time, so I was thinking that it would be nice to have 18G of water on-board (12 in cold water tank, 6G in water heater). However, once the cold water tank is empty, it doesn't seem possible to get water from the hot water tank. This effectively limits me to carrying 12G of usable water and 6G of inaccessible dead weight.

To make maters worse, if I happen to actually use the water heater, now 1/2 my usable water is scorching hot and not great for drinking.

I can only see 1 valve in the hot water compartment that isolates the hot water tank from the cold supply, but this simply leaves me with 12G cold water and wasted cargo space.

Is this the typical operation of the hot water heater? Is there a way to access all 18G of water on-board or to isolate the hot water tank from the cold-water tank and only draw from the hot tank when the hot tap is used?

Best bet is to forget the idea of using the hot water tank water. That can damage the unit and that water might not be the best.

Just get so jugs to haul extra water. I go many places without hook ups. I have a 16 foot scamp. It has the 6 gallon heater and a 12 gallon pottable like yours. I have two 6 gallon jugs I got from walmart. I hare gone through a set of these already because I kind of abuse them. I then have a 12 volt pump that I can use to refill the pottable tank. Originally I just sucked from the jugs, but I took the cap from one that failed and put a nipple on it for the hose from the pump and then I can just place the jug on something to hold it up and put it like upside down and it pumps into the tank. Works great. That is how you want to handle this.


By the way remember you have a gray water tanik and you will need to deal with that when it is full. And it holds a bit over 24 gallons or two potable tanks. So you are limited there anyway. I find I can easily make if 4 days if I am reasonable. I have done about 8 with a little effort when more water or dumping was not an option.

[redbarron55]

I installed a tankless water heater for two reasons.
1. Save money,
2. keep LP gas out of the cabin area
3. not store 6 gallons of "dead water" in the heater.
4. Endless amount of hot water (when hooped up)
5. Quieter.
6. well, maybe more than two...

[computerspook]

Originally Posted by Iowa Dave

Here you go
A little piece of clear plastic hose slipped over the end of the petcock and you’re good to go after you reduce the pressure and cool the water if you’ve heated it up
Iowa Dave

Google: RV Anode with petcock

There is a reason you need to regularly flush your water heater. That is not the best water especially with any way that you could drain water out. You would probably need to take a water filtration unit with you.

[Iowa Dave]

The man asked for a way to drain the tank. I answered his question. Criticism followed. Hmmmm.

I’ve been pretty parched when I worked in the Selway Bitterroot Wilderness over 50 years ago. We scooped water out of seeps and removed the liner from our hard hats , we put a handkerchief across the hat and strained the grit out. Once in a while we would find a Garnet in the black sand. But the water was sweet and we never got sick. Your milage and your tolerance and your luck may vary.
Always stay above the cows in open grazing country.
If you really need water your concerns change.

Iowa Dave

[computerspook]

Originally Posted by Iowa Dave

The man asked for a way to drain the tank. I answered his question. Criticism followed. Hmmmm.

He also said he was a newbee and didn't much about this.

He was specific in that he was wanting this so he could drink it and use it for consumption.

You were dead on regarding how to drain it. But the warning about the quality of this water was needed.

[Jann Todd]

Originally Posted by Scamperino

New scamp owner here. I just got a 2016 13ft scamp. It has a 6 gallon hot water heater and a DC demand water pump. No hand pump.

While familiarizing myself with the setup I noticed that when you use the hot water tap, the 6G tank is always back filled from the 12G cold tank.

I will be boondocking the majority of the time, so I was thinking that it would be nice to have 18G of water on-board (12 in cold water tank, 6G in water heater). However, once the cold water tank is empty, it doesn't seem possible to get water from the hot water tank. This effectively limits me to carrying 12G of usable water and 6G of inaccessible dead weight.

To make maters worse, if I happen to actually use the water heater, now 1/2 my usable water is scorching hot and not great for drinking.

I can only see 1 valve in the hot water compartment that isolates the hot water tank from the cold supply, but this simply leaves me with 12G cold water and wasted cargo space.

Is this the typical operation of the hot water heater? Is there a way to access all 18G of water on-board or to isolate the hot water tank from the cold-water tank and only draw from the hot tank when the hot tap is used?

The hot water tank is just like your tank at home. Use some and it gets replaced. Just carry some extra water in jugs to refill the cold tank with.

[Mr.T]

On my 2021 13' Scamp there is a low point drain valve for both the hot and cold lines (left side, under the floor near the edge of the fiberglass side, 1/4 turn ball valves).

When we're done camping I routinely drain the water heater by removing the sink faucet aerator and opening the hot faucet valve (to vent air into the water heater), then opening the cold drain valve siphons out the water heater. None of this is in the manual, I just figured it out.

Back to the original question: One could siphon the water into a bucket per above, pour it back into the fresh tank, then close the hot water tank inlet valve.

[computerspook]

Originally Posted by Mr.T

On my 2021 13' Scamp there is a low point drain valve for both the hot and cold lines (left side, under the floor near the edge of the fiberglass side, 1/4 turn ball valves).

When we're done camping I routinely drain the water heater by removing the sink faucet aerator and opening the hot faucet valve (to vent air into the water heater), then opening the cold drain valve siphons out the water heater. None of this is in the manual, I just figured it out.

Back to the original question: One could siphon the water into a bucket per above, pour it back into the fresh tank, then close the hot water tank inlet valve.

Still have to wonder why. Just take extra water. It would be safer, easier, and would taste better.

[computerspook]

Originally Posted by Mr.T

On my 2021 13' Scamp there is a low point drain valve for both the hot and cold lines (left side, under the floor near the edge of the fiberglass side, 1/4 turn ball valves).

When we're done camping I routinely drain the water heater by removing the sink faucet aerator and opening the hot faucet valve (to vent air into the water heater), then opening the cold drain valve siphons out the water heater. None of this is in the manual, I just figured it out.

Back to the original question: One could siphon the water into a bucket per above, pour it back into the fresh tank, then close the hot water tank inlet valve.

Actually I have a sink to hose adapter and a short length of hose. Then I pump the water out the window onto the ground. I generally only drain the hot water heater at the end of the season. I have been told this will make them last longer.

[Mr.T]

Originally Posted by computerspook

Actually I have a sink to hose adapter and a short length of hose. Then I pump the water out the window onto the ground. I generally only drain the hot water heater at the end of the season. I have been told this will make them last longer.

When we left the water in the heater (during camping season), the hot water often came out initially looking a bit dark and metallic tasting. The anode in the water heater didn't look that good either after only a few months. Now that we are draining the heater each time, the hot water always seems good and so does the anode.

Originally I came up with this as a part of a quick winterize for fall camping, for towing when it was potentially below freezing. Now we just siphon out the water heater every time regardless of the season. Less weight, appears to be less corrosion, and it's part of our quick winterize too.

[computerspook]

Originally Posted by Mr.T

When we left the water in the heater (during camping season), the hot water often came out initially looking a bit dark and metallic tasting. The anode in the water heater didn't look that good either after only a few months. Now that we are draining the heater each time, the hot water always seems good and so does the anode.

Originally I came up with this as a part of a quick winterize for fall camping, for towing when it was potentially below freezing. Now we just siphon out the water heater every time regardless of the season. Less weight, appears to be less corrosion, and it's part of our quick winterize too.

I kind of ended up with the inverse result. I have never had a problem from leaving it in. Did get bad tasting water from draining it. Also that adds to the time to get rolling. I keep my tanks bleached so I can fill my potable and jugs and use that time to put the other stuff in the camper I will need. Most of it is already stored in the camper. So I can be rolling to an incident in about an hour with all I need for about 5 days on site without supplies.

[Glenn Baglo]

"Don't drink the water. Fish p*ss in it".