2015 Thor Tuscany 45AT Heated Holding Tanks

[ez2jinx]

2015 Thor Tuscany 45AT. I have two thermostats in the basement. One that controls the basement heating by way of the aqua hot heat exchanger with the inside aqua hot switch on to “burner” for this feature to work. The other basement thermostat is an aqua hot thermostat that controls heat to the holding tanks. My question would be: is the heating for the holding tanks done by electric pads or by the hot tubing or another heat exchanger ? Do I need to use the inside aqua hot switch to be on either “burner” or “electric” for this feature to work. Manual has no specific instructions.

[TurnerFam]

not owning an aqua hot system, but understanding that your holding tanks are already within your basement environment - either heating the basement itself, or using the electric element for the tanks themselves, will keep the tanks above any freezing concern.

I would suspect that if you are plugged into shore power, the electric tank heaters would be the way to go - if temps are REALLY going to be that terribly low for a terribly long time.
If you are not on-grid, then using the aqua hot burner to keep the whole basement warm would suffice.

While our Palazzo uses more of a 'passive' tank warming system, which is basically a furnace vent to the basement from the propane furnace, but ONLY when the furnace is being used. There is no separate 'heating' element or tank pads for the holding tanks.

What I would admit, though, is that it's very highly unlikely that either holding tanks will be in any rare situation when the outside temps are so low, for so long, that the interior of the basement would drop to such low temperatures that the holding tanks would come anywhere close to 'freezing'. Most of us who've had issue with 'freezing' while camping or full-timing is typically only the outside water hose we either forgot to remove for the night, or forgot to insulate.

We've traveled in ALL kinds of whether, and have full-timed, like right now, when overnight temps fell well below freezing for many, many hours, if not all day long, and have never had any issues with our fresh water tank, or holding tanks. Interior tanks rarely have any issues with low outside temps, unless you've left an outside door open.

[lwmcguir]

I have a Tuscany 42GX which is similar with the same 400D Aquahot

The 42GX has two heat exchangers on two thermostats for the basement area

One towards the front and one towards the tank area

Cold weather camping requires the Diesel burner due to the exchangers required BTU to heat

Mine is a 2016 so it will be interesting to hear from others that have an AT since I don't have heat pads

On other units we have owned the heat pads were on breakers without thermostats

[ez2jinx]

Just to add:
The cold weather is coming and I would like to get this right so the tanks don't crack. If this feature is just as simple as a heating pad, then it should have a fuse some place, and I am not able to find such a fuse. If it is another heat exchanger... I only see the one towards the front of the coach, I don't see one on the back end or by the holding tanks. Would like to know if I need to keep the "burner" or ”electric" switch to on during the freezing weather.

I couldn’t get an answer through the Thor Custom Care. If the subject you’re looking for is not in the User’s Manual, you won’t get an answer. I wasn’t surprised with the non-answer.

Answered my own question: Today was a nice day to get under the Coach. There is a removable panel in front of the storage tanks. It became obvious this is part of the hydronic heating system with a heat exchanger attached to the ceiling daisy chained to the other heat exchangers within the loop. Servicing the heat exchanger would be through the wet bay and not through the removable panel. I saw no heating pads. So this answers my question… you must have the indoor switch to “burner” for this holding tank heating system to work.

[TurnerFam]

I think you're overthinking this and creating an issue in your mind about 'cold' weather, as RV across the country are in the 'cold' weather all winter and have no such thing as 'cracked' holding tanks - that's not a thing.

[Harolds931]

Why does my pump to the water tank freeze, not the tanks, just the water pump

[Harolds931]

I’m having to put heat lamps in the pump area

[EA37TS]

Originally Posted by TurnerFam

I think you're overthinking this and creating an issue in your mind about 'cold' weather, as RV across the country are in the 'cold' weather all winter and have no such thing as 'cracked' holding tanks - that's not a thing.

There was someone a few year ago that had their tank gate valves freeze and beak.

[16ACE27]

Originally Posted by Harolds931

Why does my pump to the water tank freeze, not the tanks, just the water pump

You mean the pump FROM your water tank?

Simple - thermal mass.

It takes waaaay longer for all that water in the tank to fall to and below freezing than it does for the teaspoon of water in the pump, or the small quantity of water in the 1/2" diameter PEX to reach freezing temperature.

And that's without taking into account the physical locations of the items in question.