Seneca holding tank heaters...

[Mountain Cajun]

Picking up our new 2016 Seneca HJ tomorrow. Window sticker says "Heated Holding Tanks". Afraid dealer may BS me. Are these heated with pads or only when furnace is running. Also, Heat Pump ac's, do they heat down to 40ish outside air or do you need to run the furnace? Not sure about these Heat Pump ac's or the tankless water heater. Too old school I guess.

[Robbbyr]

I have a '14 37TS and I believe the tank heating method is the same on the newer Senecas. The tanks are indeed heated by the furnace, not electric tank pads like some other Jayco motorhomes. So in sub-freezing weather it is important that you use the propane furnace so warm air is circulated to the basement area(s). Above freezing it is acceptable to use electric supplemental heaters (rather than burn propane) but if it is below freezing you need to move some heat down.

My heat pumps do indeed work to about 40 degrees outside. Colder than that the compressor shuts down and there is logic that will fire the furnace if the front thermostat isn't satisfied by the heat pump.

Now the water heater is a whole other topic. Multiple threads on these units on this forum. Some love them, some hate them. I was in between, mine worked fine if I was on full hookups and could afford to "waste" water. Generally you have to maintain steady water flow continuously during your shower or the temperature fluctuates significantly. No "Navy" or "GI" showers! Since I dry camp frequently I needed a water heater that allowed a trickle flow without shutting down on the high-limit safety then giving you a cold water blast until it reset and warmed back up. So very recently I changed my water heater to a 10-gallon Atwood XT tank-style unit. I did the work myself, all that is left is to get the new exterior door painted to match my unit (see below).

Overall I love my Seneca, it is our third Class C and it drives like a dream. Better fuel mileage than my former Ford Class C units and you don't even know you are towing a car!

Please feel free to post any questions, chances are one of us here has already "been there, done that"!

Happy travels!

[WaltW]

Rob, Jayco has installed a 6 gal tank type in my 2015 FK. I thought they used the 6 gal because there wasn't enough room for 10 gal. Now I'm thinking they did the 6 gal only to minimize their costs. How much space did you have to work with?

[Robbbyr]

Walt,
On my TS the water heater is contained in a compartment that actually could be configured as a pass-thru. On the driver's side it is for the WH. On the passenger side it is a storage compartment with the pass-thru blocked by a cover. Behind that cover in the pass-thru (over the frame rails) there isn't anything except the cold and hot water pipes leading to the heater. The area of this compartment for the WH was about 20" wide inside, and about 27" deep disregarding the pass-thru. It was probably 24" high or so. The actual opening to that compartment (behind the outer skin) was about 18" wide. Plenty large enough (in my unit) to accommodate any Atwood or Suburban.

It would have taken less work to adapt a 6-gallon unit, but I wanted more capacity. So after carefully researching heaters I decided on the 10-gallon XT. It has the electric element too so I could heat my water on campground power when available. something the tankless unit was lacking.

Attached is a link to the Mods forum where I described the install. It also has a picture of the original opening (after the Girard removed) so you can somewhat see how large it is inside. Here is the link: http://www.jaycoowners.com/forums/f3...7ts-31841.html