I have a new to me 2007 Winnebago adventurer 38t, with "heated holding tanks" option. It is plugged in and stored 24/7 in an RV park with 50 amp power. My question is can you turn the holding tank heat on and off independently of the main heaters? Or does it just engage automatically when the basement heat is turned on? With cooler weather fast approaching I was planning on heating the coach with oil filled radiator type heaters and a fan blowing behind them. But was wondering if I have to keep the main coach heater on to heat the holding tanks?? I was hoping by keeping it plugged in and cabin heated, I could bypass the full winterization process. We plan on using it the occasional weekend over the winter.
If you want to *study* how they work, I suggest that you plug into a 20 or 30 amp circuit ... and watch the amperage when you turn them on and off ... if the amperage draw increases when you turn them on then they are electric and work off from 120 V AC ... which I suspect they do.
If you dump your holding tanks before you "park" and pour some windshield wiper fluid in each holding tank they will not freeze until it gets to below zero. So depending on how expensive your electricity is you can decide whether it is cheaper to turn on your heated tanks or pour a half gallon of windshield washer fluid in your gray and black tanks. I have done this every year for the past 15 years and never had my holding tanks freeze. I use windshield washer fluid because it leaves less residue behind than RV antifreeze and is just as effective. I only use RV antifreeze in the fresh water system.
The heated holding tanks will only be important when you are actively using the rig ... and the temperatures are below freezing (actually probably below the mid 20's).
I have the winter package option on my Windsor which includes heated pads under each of the holding tanks plus a heater inside the wet service bay.
Both are activated by a separate switch called System Heat. The tank pads will come on immediately but the heater in the service bay operates with a snap disc such that the temperature must get low enough for the snap disc to close before that heater turns on. Once the temp rises in the service bay the snap disc opens and the heater turns off. I'm not sure what the low and high temps are for that snap disc but I am guessing about 40F on and about 55F off.
I also have an Aqua-Hot radiator located inside the tank bay which keeps the air warm around the tanks. It has its own thermostat.
The one has no thermostat, but is only 200w which, IMHO, is ideal for the holding tank. Otherwise, it is UL list and has overheat protection. You can read the description on Amazon for additional details.
2013 Itasca Sunstar 26HE, 2014 Honda CRV with Roadmaster tow package, RVing on weekends and vacation since June 2012