tank heaters

dan76 · 01-12-2015, 10:54 PM

We are getting ready to head south from northern Indiana. at what point can I put water in tank. do tank heaters work on 12v? how are they activated?
thanks in advance for you response!!

Dan76

**Mr. Dan** · 01-13-2015, 02:56 PM

I've learned that information which applies to one unit does not apply to another and you gave no information about what unit you have... but my tank heaters are turned on by a rocker switch that was added near my control panel... near my slide switches and tank level lights. My switch has a red light in it to indicate when the heaters are on. Heaters are 12v on mine. This topic has been discussed much here this winter. Do a Search for "tank heaters" or some such and learn much.

I'm not sure what you mean by "at what point can I put water in tank"... relative to what? condition of tank? temperature? location?

rana · 01-13-2015, 03:13 PM

Just to make sure we are on the same page.. there is a difference between "heated tanks" and "tank heaters". Some rigs have "heated tanks".. meaning that the underbelly is heated via heat ducts coming off your furnace, and "tank heaters" are 12v heating pads directly on the tank itself.

For tank pads, they are activated by the rocker switch, but are thermostatically controlled. Typically, they will switch on once the tank temperature drops below 40 degrees. Note that the underbelly temperature may actually be higher than the ambient temperature.

If you have heat pads, then you can add water to your tanks whenever you wish. For "heated tanks" you don't want to introduce water into your plumbing until you are going to be running your furnace.

fonzie · 02-23-2015, 06:33 PM

Here is some info on tank heaters or if someone ever needs replacements.

Products from Lasalle Bristol :: RV Outlet Mall

DaveSchwartz · 02-23-2015, 09:41 PM

Quote:

Originally Posted by Yarome

If you have heat pads, then you can add water to your tanks whenever you wish.

According to recent experience of mine, that's not quite true.

2015 Rockwood 8282WS - pulled into an RV park in Marieta GA last Thursday night and it was about 10F (-9C). We were advised not to hook up to the water system because the run from the (heated) hydrant to the RV would freeze - just to put some in the enclosed, heated FW tank. That was our plan anyhow.

However, there seems to be some one-way valve in the fill pipe that is temperature sensitive - maybe a polymer hinge that stiffens up and no longer opens at that temperature? Water just came gushing back out at and on me (where it promptly froze) and none went in the tank.

Anyone experienced this before? What was FR thinking?

Once the temperature rose into the 40's Saturday, no problem getting water into the tank.

We ended up connecting the water line and doing the old trick of running a trickle of water in the bathroom sink (moving water takes much lower temperatures to freeze). Fortunately, the services were right beside the hookups on the RV so I made a water line that was only about 4 feet long and the sewer hose was only about 3 feet on a 45 degree angle (because it had to be kept open so the water trickle didn't fill the gray tank.

OldCoot · 02-23-2015, 09:53 PM

Quote:

Originally Posted by DaveSchwartz

According to recent experience of mine, that's not quite true.

2015 Rockwood 8282WS - pulled into an RV park in Marieta GA last Thursday night and it was about 10F (-9C). We were advised not to hook up to the water system because the run from the (heated) hydrant to the RV would freeze - just to put some in the enclosed, heated FW tank. That was our plan anyhow.

However, there seems to be some one-way valve in the fill pipe that is temperature sensitive - maybe a polymer hinge that stiffens up and no longer opens at that temperature? Water just came gushing back out at and on me (where it promptly froze) and none went in the tank.

Anyone experienced this before? What was FR thinking?

Once the temperature rose into the 40's Saturday, no problem getting water into the tank.

We ended up connecting the water line and doing the old trick of running a trickle of water in the bathroom sink (moving water takes much lower temperatures to freeze). Fortunately, the services were right beside the hookups on the RV so I made a water line that was only about 4 feet long and the sewer hose was only about 3 feet on a 45 degree angle (because it had to be kept open so the water trickle didn't fill the gray tank.

I think he is talking about the holding tanks, not filling a fw tank. We just experienced 7° temps here and I never winterized anything and never had a frozen pipe. I ran an electric EdenPure heater on 2 notches from the highest and ran the furnace blower (not the burner) with the tank heaters on. Just drained the camper today when the temp got to 45°.

frozen · 02-23-2015, 10:37 PM

Even though tank heaters (12 volt pads) are effective at preventing frozen tanks, there's a lot of unprotected plumbing that is subject to the cold unless furnace heat is also blown into the underbelly. The underbelly itself provides some protection if it's not real cold for many hours, but, hey, water begins freezing around 32.
I wonder if DaveSchwartz's inability to fill his fresh water tank was caused by an ice blockage in the fill line rather than a "one-way valve". Is there such a thing?

Dave_Monica · 02-24-2015, 01:03 PM

Quote:

Originally Posted by frozen

I wonder if DaveSchwartz's inability to fill his fresh water tank was caused by an ice blockage in the fill line rather than a "one-way valve". Is there such a thing?

I could have been a frozen check valve on the city water inlet which is required to prevent fresh water from leaking out when running the FW pump.

Dave

DaveSchwartz · 02-24-2015, 02:12 PM

The FW tank was thoroughly drained in October and it went above and below zero a number of times before Christmas so I can't imaging there was any water in the fill pipe to freeze.

The FW tank inlet is on the extreme back right (tank is also in the rear) on this model and the city water is forward left-side so I can't see how there is any connection until the check valve at the water pump.

Its a mystery!

frozen · 02-24-2015, 02:44 PM

DaveSchwartz, It might be possible that there's a low spot in the fill line, so a "plug" of ice could occur. I've had a slightly different problem with FW tanks on two Rockwoods; the FW tank vent tubes have had low spots in them. Once the tanks were filled, water got into the vent tubes preventing them from doing their job, making it impossible to completely fill the tanks. That caused water to fill what I assumed to be low spots in the fill tube. To resolve that problem and to amusement of everyone in the campgrounds, I put my mouth over the fill opening and blew hard, then got out of the way because water would shoot back out through the fill opening. After "burping" the tank, more water could be added. Seems like a simple vent tube should work a little better than that.

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