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Topic: Help understanding the HEAT options for my Bus (Read 990 times) previous topic - next topic

Help understanding the HEAT options for my Bus

Hi all!

I am contemplating taking my bus on a trip to Colorado this week. I have never done any cold weather travel in it. We will be using it for transportation only, I rather drive my Bus then my Suburban, and my wife agrees!

I started the generator today and put 1 zone furnace and 2 zone heat pump wondering if things would simply warm up. NOPE. I do have an aqua hot but the water section is no good, not winterized correctly by the previous owner. I have not tried just the heat mainly because I do not understand it completely. I would love to figure all of this out and do more winter traveling (aka SKIING).

Any thoughts and ideas would be greatly appreciated!!
2000 U320 36'
Build #5705

Re: Help understanding the HEAT options for my Bus

Reply #1 –
If it's just the potable water portion of the aquahot that is damaged or leaking then the coolant portion may be ok and still provide heat.  You have 3 options for aquahot heat:  120Vac, diesel, and heat from your engine when it is running.  Look on the cabinet under the stove for the switches.  If plugged into shore power or when running generator you can use the 120Vac element.  Otherwise use the diesel but since the previous owner had problems it may not operate properly, either not fire up or put out black smoke.
When you're driving down the highway the aquahot should be hot enough from the engine coolant to provide heat.  Assuming that the PO has not shut off those valves.
If all else fails use the heat pumps and a couple of small electric heaters. But heat pumps won't put out much heat if the ambient temp is 40 or below.
BTW the furnace option on the front thermostat is for the aquahot but it needs to have heating from either of the 3 sources above.
Before you turn on the aquahot I'd check the plastic overflow bottle in the middle large basement, usually on the passenger rear side.  If it doesn't have any coolant in it the tank may be dry from leaking. In that case you won't have any aquahot heat.
Good luck.  Rudy Leggett is the go to guy for all things aquahot!
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell

Re: Help understanding the HEAT options for my Bus

Reply #2 –
The coolant for the Aqua Hot is independent of the freshwater. The heater would work if the other components of the AH are functioning. In our case no hot water is a deal breaker on traveling but that is up to you.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Help understanding the HEAT options for my Bus

Reply #3 –
I run the Generator and use three 1500 w Electric heater one in the front one in the bathroom and one in the bedroom plus  the coach heat on the windshield to defrost it
Rick & Hilda looking forward to full- timing one day for now couple of months at a time
1999 U270 3602
Built number  5530.  Feb 1999            Motorcade  number 18438
8.3 Cummins Allison six speed with brake  retarder
Purchased Nov 28 2019

Re: Help understanding the HEAT options for my Bus

Reply #4 –
If your AH runs on diesel then set the front thermostat for zone 1 [LR) to 75 or higher and the zone 2 (BR) to 65 or so. Leave the diesel on even while driving and the heat exchangers will heat the coach.  The front zone gets set high to prevent dash heat from fooling it into thinking the LR is warm enough.

If the diesel burner doesn't work then the electric heater will only keep up down to the low 40s. (For some maybe 50s)

In either case if the hot water side is not working that will make travel more difficult.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Help understanding the HEAT options for my Bus

Reply #5 –
If the Aqua-hot isn't working you would want to drain and winterize the water system The generator can keep the coach warm as
Rick said using electric heaters In the winter. When I'm running the generator to charge the batteries I run the Aqua-hot on electric
and 2 electric heaters. I plug one in under the coach and the second one in front of the small table, that way they are on separate
circuits. The bedroom I've never used a heater there so I haven't looked for a separate circuit there. If the Aqua-hot isn't working
Rudy will be the best to talk to. If it is full of antifreeze you can use it to heat the coach when engine is running.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Help understanding the HEAT options for my Bus

Reply #6 –
Quote from: Roger & Susan in Home2 –
If your AH runs on diesel then set the front thermostat for zone 1 [LR) to 75 or higher and the zone 2 (BR) to 65 or so. Leave the diesel on even while driving and the heat exchangers will heat the coach.  The front zone gets set high to prevent dash heat from fooling it into thinking the LR is warm enough.

If the diesel burner doesn't work then the electric heater will only keep up down to the low 40s. (For some maybe 50s)

In either case if the hot water side is not working that will make travel more difficult.


More difficult? I bypassed the water and have that running through a small electric water heater. I will likely drain everything because I will have the Bus parked for days while in CO.

I will attempt the diesel portion of the AQ tomorrow. I think Rudy told me it would not work without new nozzles but I will try it.
Is there no heat that comes from the roof top units when the generator is running?
2000 U320 36'
Build #5705

Re: Help understanding the HEAT options for my Bus

Reply #7 –
The heat pumps won't work in the cold. Do more than just drain the water out of the coach. There are forum members than can
run you through the winterizing process as I have never done it as I use my coach in the winter and I know how to do that so I
don't freeze the water system.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Help understanding the HEAT options for my Bus

Reply #8 –
Quote from: oldguy –
The heat pumps won't work in the cold.

To expand on this further, the heat pumps are just your roof air conditioners working in reverse.  Their function is to move heat from one area to another.  On air conditioning, they move heat from the interior to outside.  On heat pump, they move the heat from the outside to the interior.

Now think about that a moment.  How much heat is there outside when it's really cold?  Not much.  That is why heat pump mode really doesn't work well when outdoor temperatures drop below 40F.  There simply isn't enough heat in the outdoor air to "capture" and transfer to the interior of the coach.  At moderate conditions in the high 40's to the 60's, heat pump mode works well if you have unmetered shore power and don't want to use the diesel side of the AquaHot.

The heat pumps also won't keep basement contents/plumbing from freezing since they don't provide heat to the bays. 
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Help understanding the HEAT options for my Bus

Reply #9 –
Also you can not have one zone on furnace and the other on heat pump. The comfort control will not allow that with the 4 button or 5 button thermostat.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Help understanding the HEAT options for my Bus

Reply #10 –
Quote from: Michelle –
To expand on this further, the heat pumps are just your roof air conditioners working in reverse.  Their function is to move heat from one area to another.  On air conditioning, they move heat from the interior to outside.  On heat pump, they move the heat from the outside to the interior.

Now think about that a moment.  How much heat is there outside when it's really cold?  Not much.  That is why heat pump mode really doesn't work well when outdoor temperatures drop below 40F.  There simply isn't enough heat in the outdoor air to "capture" and transfer to the interior of the coach.  At moderate conditions in the high 40's to the 60's, heat pump mode works well if you have unmetered shore power and don't want to use the diesel side of the AquaHot.


I do understand heat pumps...When in heat pump mode shouldn't it be blowing out the rooftop unit? I guess that is what has me puzzled.  Maybe it is what was latter said that both zones need to be in the same mode.?.
The heat pumps also won't keep basement contents/plumbing from freezing since they don't provide heat to the bays. 
2000 U320 36'
Build #5705
 

Re: Help understanding the HEAT options for my Bus

Reply #11 –
One other thought, with your coach being a 2000 are sure you don't have regular A/C units with heat strips rather than heat pumps. I know of a couple "00" that have regular A/C units. As RT said, either way they have to be set correctly at the thermostat.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."