Facon 12" x 18"12V RV Tank Heater Pad with Thermostat - 2Pack, 12Volts Heating Pads Prevents Freezing for 50 Gallons Fresh/Grey/Black Holding Water Tanks, QAI Certified

We have converted a MWB van. As such we need all the space we can get inside and didn’t want to take it up with water tanks. The only downside to the tank being set outside and under the van is the likelihood of it freezing in colder temperatures. These pads have resolved that issue. Teamed with lagging the pipes and insulating the tanks we have no issues with freezing.

High quality. Washed the bottom of the tanks and the peel and stick went perfect. Fuses are a nice addition.

Ordered four of these for my travel trailer. 60 gallon potable 30 gallon black 30 gallon grey 1 30 gallon grey 2 Installation was easy once you get access to the bottom of the tanks and run the wires. However, the overall installation takes a while and is somewhat difficult for most. I would not even bother with the included fuse holders (you get one fuse holder for every two pads when you order this product). Just use a spare space (I used two, pot/black and grey/grey)) at your load center. I decided to use a 3 switch panel. One for potable, one for black, and one for both grey tanks. Since I had access, I went ahead and also installed a reflective thermal layer under the tanks. Its the thin stuff that is basically thin bubble wrap cover in foil. Each tank needed 2' x 5' for good coverage between frame and joist sections. They sell it on Amazon for 2'x10' roll for like ten bucks. This helps reflect a fair amount of heat back up. Cheap, easy add on. The power consumption is roughly as advertised. If you are on shore power, then no problem. Run them all if you expect freezing temps. However, if you are not on short power, be aware that all four pads will use up quite a bit of battery power. They are roughly 5A each. I tend to worry more about potable water tank and lines freezing up, so I only run that one when on battery. In the morning when its time to head out, then turn off potable and run the black and grey to thaw out if they froze. These pads work remarkably well for such low wattage. Switching them on means you have armed them. They wont activate until the temperature as sensed by the pad sensor reaches 45F. It will then run until that sensor reaches 65F and deactivate. It will repeat this cycle as long as they are armed. On a recent trip, we got an inch of snow followed by 36 hours below freezing temps. Mostly 16F-25F or so. Before and after that period we were seeing low 30's for at least 24 hours ahead and behind. These pads worked like champs in conjunction with running the furnace. No issues with water lines. The only freezing we got was with our grey 2 dump valve. That section of pipe and valve runs a good 2 feet outside the protected zone, and it will need its own insulation/heater. The valve was a little stuck with ice behind it. Got it open. First you could hear the slush push through, and them voom. The water in the grey tank itself was quite warm and cleared that all right up. The only other issue was with blank tank flush. It seems some freezing may have happened with some of the jets. Next day it was fine. Otherwise, black dumped no problem. For 30 gallon, one pad is plenty. For the 60 gallon tank I almost feel like I should have gotten two for it, although one pad has worked for us. The black and grey tanks were unobstructed on the bottom where the pad mounts. Note, you cannot stick the pad to anything metal according to the instructions. On the 60 gallon, there are metal straps that wrap the tank for support. You cannot stick the pad to that. However, there was at least two clear sections for me to put pads. For all tanks, you should stick the pad near the outlet. Potable had one there, and then another spot mid-tank and maybe a third spot at the other end. If I would have gotten the longer and skinnier pads also made by this company, they would have worked for black and grey but not the potable tank. Only 12x18 works on my potable tank, and at least two pads can fit and not be on a strap. If you are not sure about the geometry and support strap location of your tanks, I recommend you get these vs the the long and skinny ones (7x25 ?). Overall, I am happy with these pads so far. If you have the opportunity, get a peak underneath before ordering. If you dont, the 12x18 are the safer bet. If you will be using these off grid for any length of time, you will need to up-size/add batteries almost guaranteed. One group 24-ish battery will simply not cut it. Two group 29/31-ish or more would be the bare minimum, IMO.

Bought 3 packs of them. One for each gray tank, one for the black, two for the larger freshwater, and one spare. They work perfect. I’m a techie so I wired them into a Blue Sea fuse panel with a resettable breaker as a safety measure. Otherwise, I used the provided fuses and can confirm the built in thermostats work. My Mopeka tank sensors were reading 48° F on the outside when ambient temps were below freezing these past few weeks. Easy to install - clean the surface with mineral spirits then alcohol and stick away. I put HVAC tape around the edges to be extra. Andddd Done. I definitely recommend.

Delivery was quick and all is good.