2021 View 24J Holding Tank Heaters

[PKVIEW24]

Hi - Newbie with 24J - holding tank heaters were left on overnight with ~30deg temps. Tanks were empty - on shore power. Now Cabin batteries are drained.

how to know if i damaged tanks?
how to get batteries back to charged?

[Eagle5]

Hi PkView24,
There is no way that your tanks are damaged. The amount of heat from those heaters is fairly minimal, and not nearly enough to melt the tank, so no worries there.
Regarding the batteries being completely drained, you need to do one of these three things to recharge your batteries ASAP:

1. get plugged into shore power
2. run the generator
3. drive your motorhome

Be sure to check your batteries' water level too.
The longer the batteries stay drained, the more damage will be done to them. Sadly, draining lead-acid batteries totally does damage them, so you have lost some storage capacity.
Welcome to the forum.
Eagle5

[PKVIEW24]

Thanks for the reply on this EAGLE5. Going after battery recharge as quick as possible.

[bigb]

On many coaches the battery switch must be on in order for the converter to be able to charge them.

[creativepart]

It will help for you to understand a couple of things about your RV.

1. It takes prolonged deep freezing weather to freeze your motorhome. One overnight at 30 degree would not come close to being cold enough to need the tank heaters. Use them if the temps are below 25 overnight and the next day will not get above 32. But if the next day is going to warm to around 38-40 degrees then you don't even need the tank heaters at all - even if it's 25 over night.

2. EVERY item on your RV that produces electric heat uses a large amount of electricity - 12v or inverted 110v. This includes coffee makers, hair dryers, microwaves, toasters and toaster ovens, and of course tank heaters. These items use electrical resistance to heat up wires and elements and that uses a ton of current to create heat. Your microwave uses electricity to operate a large magnetic device called a magnetron and that uses a lot of electricity. Your furnace uses propane to produce heat but has a powerful fan to distribute the heated air. So, even though it's not using electricity to produce heat the fan uses quite a bit of power to distribute that heat.

[creativepart]

Originally Posted by bigb

On many coaches the battery switch must be on in order for the converter to be able to charge them.

I'm assuming the same thing - if he was on shore power then his batteries wouldn't be drained from running the tank heaters. So, I'd guess he is not turning on his battery cutoff switch/solenoid.

Turn off your batteries only when putting the RV in storage. Never when you are using it.

[David_Laura]

I've been thinking about installing heating to my water tanks using some sort of heating pad (120v). Exposed surface area appears to be limited which complicate installation.

My question is: What types/brands of heaters are available, or used by Winn?

[bigb]

Originally Posted by David_Laura

I've been thinking about installing heating to my water tanks using some sort of heating pad (120v). Exposed surface area appears to be limited which complicate installation.

My question is: What types/brands of heaters are available, or used by Winn?

Mine are Ultraheat brand 12 volt but their website shows 120 volt as well. You only need to cover a small area, mine are about 6"X14".

There are some cheaper brands out there, Ultraheat seems to be the most expensive but claim to be the best.

[prreuben4]

Originally Posted by Eagle5

Hi PkView24,
There is no way that your tanks are damaged. The amount of heat from those heaters is fairly minimal, and not nearly enough to melt the tank, so no worries there.
Regarding the batteries being completely drained, you need to do one of these three things to recharge your batteries ASAP:

1. get plugged into shore power
2. run the generator
3. drive your motorhome

Be sure to check your batteries' water level too.
The longer the batteries stay drained, the more damage will be done to them. Sadly, draining lead-acid batteries totally does damage them, so you have lost some storage capacity.
Welcome to the forum.
Eagle5

Hello, just seeing this, December of 2023, and just heading into a few weeks of at or below freezing temps for the first time. Have a 2020 Minnie Winnie on an E-350 frame, and we’ll have shore power for most of that time. Why would keeping the holding tank heater on overnight drain the cabin batteries? Also, does the heater protect all three holding tanks for fresh, black and gray? Is it safe to leave the holding tank heater on continuously overnight? What other precautions will help avoid freezing water lines? Thanks.

[Eagle5]

Hi prreuben4,
On page 7-7 of your Owner's Manual, Winnebago says that the black and gray tank heaters draw a significant amount of 12 VDC, and that without Shore Power, Generator Power, or driving the motorhome, your batteries would not make it through the night.
Your fresh water tank is inside the heated area of your motorhome, so no need for a fresh water tank heater.
If you keep your motorhome heated, you should not have any issues with nighttime freezing temperatures. When it is freezing, be sure to use your internal fresh water tank, and unhook & drain your water supply hose.
Do you have a 22R or a 22M?
Welcome to the forum.
Eagle5

[Morich]

Winter is often a thing of mystery and it can trick us in lots of ways, so we have to stay alert!
But there are some general "rules" that apply to home as well as RV and we can use that.
To freeze water we need to get it below 32. Obvious, right? But one big point that is often missed is a small amount of water cools much quicker than a large amount.
Set a cup of water out on the edge of a swimming pool and the cup freezes way before the pool!
So in an RV, the tanks are among the last things to freeze for a couple reasons.
They are semi-inside in the storage compartments except for where the lines and fittings stick outside and the big thing is that they are also huge amounts of water compared to things like lines, faucets and other connections.

One of the tools I use frequently is this interactive parts catalog:
https://catalog3d.winnebagoind.com/menu/Parts.htm.

When you know which year, make and model as well as sometimes the build date, you can go to the drawings for your specific model and see where the tanks and lines are placed.
You can also go to the furnace/heat section and see where the ducts run. Some have ducts placed specifically to heat the compartments, others not.
Then you need to look at what is small volumes and what is close to the outside! What is small and fragile in the coldest spots?
Spots that tend to freeze to break are those which are way far away from any heat ducts or runs as well as small things that break. Usually the tanks don't fit that setup but the line way far in back somewhere running up the wall to the shower may be a suspect!
If we do find there is a line somewhere that doesn't get heat through the wall as well, what to do is the next trick.
First, I look at what keeps the room heat from getting to that spot. Is there a cabinet door that I could leave open at night to let air move in and up the wall? Is there a space where I could place a troublelight underneath in a compartment where the heat from the bulb would filter up the wall with the lines and keep just enough to avoid freezing?

One of the things, I learned to use is that water moves inside the pipes, with cold sinking and warmer rising. So if I can add a bulb down low to heat the line, there will be a temperature difference with the cold part up in the wall, compared to the low where I can get to it to heat it. Magic says the water I warm moves up and the water that is cool up above has to come down to be heated!
But then the things that stick out the sides of the RV, DO get cold and you have to look at those as super easy to freeze. No water hose connected without heat tape, etc. !

[Eagle5]

There are three modes of Heat Transfer:

1. Conduction (via direct contact)
2. Convection (via air movement)
3. Radiation (via deep space heat-sink)

When anything is exposed to the night sky, it radiates its heat to deep space. Going through our atmosphere, it is equivalent to a radiative heat sink of -50ºF. This is an additional reason why things like a water supply hose will freeze-up. Just as Richard says, it is a smaller volume of water so less mass to cool, but deep space radiative heat loss is another factor.
The black & gray tanks are not exposed to the night sky, so they do not need to contend with that sort of cooling.
You can block deep space radiative heat loss with something as simple as cardboard. Also, cloud cover will block radiative heat loss.
Thanks, Eagle5

[prreuben4]

Thanks for the info. Mine is a 22R.