When to use tank heaters

[ForBruce]

Okay so I just found out my trip to Georgia is going to be in very cold weather and I'm wondering what's the best way to use the tank heaters for freshwater Blackwater excetera
I take it the heaters are not in the tanks they're underneath.
is it possible to burn out the heaters if there's no water in the tank does anybody know anything about this

[Daryles]

DO NOT TURN ON TANK HEATERS UNLESS THERE IS WATER IN THE TANK.
I asked Keystone what tank heaters they used. They replied
"Thank you for your inquiry. The heater pad for the tanks is a Patrick Distribution product SL-T1218. Once you turn the switch on for the heaters, they are on. When in use, please make sure the tanks have something in them. If not using your tanks and they are empty, you will want to turn the heat pads off."

I looked up the manufacturer specs on these heating pads and found out they are 65W and do have a thermostat built into them. They turn on at 45°F off at 67°F
https://www.etrailer.com/RV-Fresh-Wa...77-000164.html

[DutchmenSport]

delete. bad info.

Daryles, you are now challenging me dig up the paper work for my camper! I know I have user manuals for the heat pad in my Montana. I've got to re-read them. Now, where in the world did I put that bag of paper?

[DadsHemi]

I don’t turn them on unless I know it’s going to be in the freezing temps the day in advance, I’ll turn them on a day before. When I drain the black tank or gray tanks I’ll add a few gallons back I them so there not dry, I’m sure even when drained they don’t completely drain but I don’t Wharton to take chances.

That’s just how I handle the freezing weather.

[RMcNeal]

As stated, the tank heaters are just a simple heating pad attached to the tank with adhesive like a peel and stick type. The have a thermostat that will activate and deactivate the heating based on the ambient temperature. I haven't looked at the book in a while, but the numbers above look accurate.
There is no need to run them when the tank is empty. When you are set up somewhere and the temps are going to dip below freezing, I would suggest turning them on. All of our tanks have some water in them even after dumping. I keep about 5-10 gallons fresh for use when travelling. Our gray tanks will typically have some residual water left after dumping, and even if not, they will quickly get some water when we get setup somewhere through normal use. The black tank always has at least 3 gallons of water even after a good dump and flush, as I purposely add water through the toilet or black flush and put in some Happy Camper stuff to help keep the tank clean. Just my $.02. YMMV.

[Theunz]

Not saying that you should leave them on with dry tanks, but I don’t see how having them on without water in the tanks could hurt anything other than drawing down your battery if you aren’t hooked up to shore power. They just don’t get that hot. It is the same principle as the seat heaters in your truck, and unless it’s raining and you left your window down there’s no water in your seats��

[Creeker]

Originally Posted by Theunz

Not saying that you should leave them on with dry tanks, but I don’t see how having them on without water in the tanks could hurt anything other than drawing down your battery if you aren’t hooked up to shore power. They just don’t get that hot. It is the same principle as the seat heaters in your truck, and unless it’s raining and you left your window down there’s no water in your seats��

You are correct. Its not like a heating element in a water heater.

[DutchmenSport]

I finally located all my Montana documentation, and I couldn't find the paperwork on the tank heaters. I thought for sure I had it though. I remember reading it. I just don't remember what it said.

I did watch a couple YouTube videos on the subject, and considering the pads have their own thermostat built in, and the are designed to turn on when the ambient temperature reaches around 40 degrees, I would think once the surrounding area reaches temperature, (no matter how much cold it has to warm up), the thermostat will turn the heat off. It might flip on and off more frequently than if there is fluid on the other side of the tank floor, but I can't see where leaving them "on" would not damage anything.

But I will admit, I used them only 1 time in 3 winters now, and turned them on only when the outside temperature reached 30 degrees and stayed there.

[mlh]

It won’t hurt anything if a few gallons of water freezes in the tanks. To test this put a plastic pan in the freezer about half full of water and see what happens. Nothing.
Lynwood

[ForBruce]

Originally Posted by mlh

It won’t hurt anything if a few gallons of water freezes in the tanks. To test this put a plastic pan in the freezer about half full of water and see what happens. Nothing.
Lynwood

your right about some water freezing...but what your not taking into consideration is the small amount of THIS water being in contact with the drain valves which are HARD plastic and not to forgiving (or flexible)

[BiggarView]

We also keep a few gallons fresh for travel days. In colder weather... which is usually night time temps, we check overnight low temp forecast before going to bed and anything under 40 mean the heaters go on., and off when we get up unless day time forecast is also below 40. Works for us so far... and we have dealt with some temps down to 15 overnight. We try to avoid such temps but heh, not always possible, that is what tank heaters are for.

[mlh]

Originally Posted by ForBruce

your right about some water freezing...but what your not taking into consideration is the small amount of THIS water being in contact with the drain valves which are HARD plastic and not to forgiving (or flexible)

I did take that into consideration. Think of all the campers that are left out without the tank warmers on or those without a tank warmer including mine.
Lynwood

[rohrmann]

We don't have tank heaters and have been in temps as low as 9 degrees and a bunch of low teens and never had a tank or valve freeze up. Of course, we were living inside which means we had the furnace going which adds some heat to the belly area. With these experiences, I don't see the urgency of having tank heaters going unless you were away from the rig for a while and wanted the furnace set real low, but that might risk the water lines freezing. I guess it's nice having those heating pads, but many of us have gone for years and have not had issues in the cold.

[kozzy]

I have never used my tank heaters. I have only 3 buttons, but 4 tanks ( 1 Fresh, 2 gray, i Black) which ones get heated? We are building a house in Florida, but it wont be ready till mid February. We have to be out of our house here in upstate NY Feb 1, so we are planning on staying in our 5re for a couple of weeks and I am thinking I am going to need the tank heaters. If anyone has any other tips useful for cold weather use, please share.

[mlh]

Probably the most useful thing about tank heaters is, the big tanks will warm the other plumbing close by and it isn’t going to freeze either. It’s like putting a light bulb in the well house. It’s not much heat but that is all it takes.
Lynwood

[RMcNeal]

Kozzy, if you are going to stay in Florida while waiting to move into the new house, you likely won't need them. I live in Jacksonville, basically south Georgia. Almost never have very cold winters anymore. I can remember as a kid having single digit days but they were very rare. I remember more Christmases in the 70's than the 30's.

[kozzy]

Not staying in Florida while I wait, I need to stay up here in NYS, work and kids school are keeping me here just a few more months..

[RMcNeal]

I just spent the last month in WV. I turned on the tank heaters when I set up and left them on. Hasn't hurt anything. I also filled the FW tank and kept the hose stored since I don't have a heated hose. Ran on the internal tank and pump. Dump gray and black about twice a week. We got down to 8 degrees a couple nights ago with wind chill to -10F. I had a little ice in the sewer pipe when I went to dump tanks. A little hot water cleared it. I did have the valve for power fill in the convenience center freeze up this time. I put a space heater in there for about 10 minutes and it thawed out. Wasn't running the furnace enough I guess.

[Rondo]

Kozzy(Ed)-- If I'm not mistaken at the last National Fall Rally or the one before that the question was brought up about the three tank warmer switches and four tanks and the answer was that the Black and freshwater have their own individual switches and the two gray tanks are hooked together on the other switch so when it is turned on both gray tank heater pads are activated and both tanks are being heated off that one switch.

RMcNeal(Robert) I have gone into the basement and removed the back wall and checked out the heat ducts coming from the furnace. I have one that ran to the toilet room (my unit has a separate toilet and sink in a SMALL room off the hallway to the bedroom). I went to one of the big name hardware stores and purchased a PVC "Y" the same size as the foil ducting, some foil ducting and a three radiator clamps. I cut the duct running to the floor vent to the bathroom and installed the "Y" with the ducting I purchased and directed it to the convenient center to add some heat in that area so the water connection and the valves in there would get some heat in colder weather. It works like a charm. I just took a piece of wire and connected it to one of the braces in the back of the convenient center and the duct and wala heated convenient center.

[RMcNeal]

OK. Just wanted to make sure I wasn't spreading any misinformation as it's been a while since I looked at the paperwork for our rig. Here's a picture of the FAQ page at the end of our tank heater manual.
It basically says turn the heaters on when the temps approach 45F. If the tanks are empty, no harm will come to the pad or tanks, but recommendation is to turn them off when empty. If left on, they will continue to cycle on/off at 45F and 67F.