Tiffin Phaeton Aqua Hot -- 400D good enough?

[DazedNConfused]

In the process of picking out a motorhome...and I keep coming back to Tiffin. Drove an Open Road Allegro...and we really liked the coach itself...but after driving a diesel it would have to be the Allegro Red or Phaeton. Looking at 38QBA or 40QKH. Anyway...in comparing the two I found that Aqua Hot is now an option on the Phaeton which is part of their "All electric coach" option at $8,120. I know it includes the Aqua Hot system...but I'll assume that means it completely eliminates all propane from the coach -- including stove. It's already using a residential fridge.

I found an article this morning that talks about which Aqua Hot. The Phaeton uses the 400D whereas the Bus uses the 450D. A quick comparison shows them to be very similar units -- same BTU rating, about the same GPM, and the same fuel consumption. But...and here is where I'm trying to determine how important -- the 400D only uses two sources of energy to heat the water -- a 1650w heating element or a diesel burner whereas the 450D can use the heating element, diesel burner, and also heat from the diesel engine. So that means the 400D in the Phaeton cannot offer cold engine start assistance...or heat the coach while travelling without using the diesel burner or running the generator. Is what it is...but was more curious about the cold starts. Only diesel I've owned has been my diesel pickup truck....and cold starts aren't an issue for it...so was looking for some feedback on whether the 400D is worth the cost of admission.

Thanks.

[Blaster_Man]

DazedNConfused wrote:

Blaster Man wrote:
One other point, if not already mentioned, the 400 is propane, not diesel.

The 400LP is propane, the 400D, which was stated in my original post, is diesel.

DNC

Correct...didn't see that.

[DazedNConfused]

Blaster Man wrote:
One other point, if not already mentioned, the 400 is propane, not diesel.

The 400LP is propane, the 400D, which was stated in my original post, is diesel.

DNC

[Blaster_Man]

One other point, if not already mentioned, the 400 is propane, not diesel.

[meuryGMC]

Here is a thought guys. I have a 73 GMC classic coach. I want to set up my own hydronic. So instead of buying an hydronic system at 6 grand i'm thinking of building my own. Here are my thoughts and questions.

1. On Demand Water Heater (Because it has 50,000 BTU) with a small two gallon storage tank. (marine grade, only has a 110 element and heat exchanger) Instead of using water in the on water storage tank and on demand hot water heater i would like to use good old pink stuff or other antifreeze. The flow would work like this.

ON Demand Water heater heats antifeeze that goes directly in the "water side" of the storage tank. and is then fed to 3 loops.
a loop for my real hot water potable water,(which is a 6 gallon water heater heated by engine heat and 110) and two loops for heating my rv via hydronic radiators.

The heat exchange in the storage tank would hooked up to the engines heater loop. This way while driving the engine would heat the anitfreeze in the 2 gallon antifreeze storage tank that could then be pumped via a 12 volt pump to the rest of the coach. The RV Antifreeze and the Hyrdonic Antifreeze never mix.

So my question is can i run the pink stuff in say an Atwood on Demand water heater since it has no anodes.?

[bluwtr49]

A huge advantage of the engine coolant loop is that with the engine preheat switch on while driving, the engine coolant heats the entire coach by simply turning on a thermostat.

Personally, I thought that was standard on all Aqua Hots and I would certainly want one.

[Blaster_Man]

DazedNConfused wrote:

StevenH wrote:
It is VERY important to PROPERLY winterize the AquaHot. You need to pump the pink antifreeze through the fresh water loop in the AquaHot. Just blowing it out can leave enough water in the loop to break it when it freezes. This will require replacement of the AquaHot (Big $$$$).

Steve

I just read the AH owner's manual. Seems straightforward enough.

Or you can drain the water and put a couple of 60w light bulbs in there. It's worked for me down to 10 degrees.

I think Tiffin is saving a couple of bucks by using smaller AHs in their coaches. Amer Coach uses nothing smaller than the 450DE and in the larger coaches uses the 650. One thing to keep in mind with the 450, if it is producing heat and you turn on hot water faucet, the heat function stops until the demand for water is no longer there. That's what my manual says, and that's how it works. The 650 can run heat and water at the same time.

[DazedNConfused]

StevenH wrote:
It is VERY important to PROPERLY winterize the AquaHot. You need to pump the pink antifreeze through the fresh water loop in the AquaHot. Just blowing it out can leave enough water in the loop to break it when it freezes. This will require replacement of the AquaHot (Big $$$$).

Steve

I just read the AH owner's manual. Seems straightforward enough.

[StevenH]

It is VERY important to PROPERLY winterize the AquaHot. You need to pump the pink antifreeze through the fresh water loop in the AquaHot. Just blowing it out can leave enough water in the loop to break it when it freezes. This will require replacement of the AquaHot (Big $$$$).

Steve

[DazedNConfused]

Thanks for all the feedback. I know trailers pretty well...but motorhomes, while they share many systems, are a different beast altogether. The Aqua Hot may be one of those instances where I won't miss what I don't know. Heard many folks say they wouldn't own a coach after having a hydronic system. I've never used one...and yet with my 10gallon water heater in my fiver, I have never run out of hot water despite long back-to-back showers from three girls. I think the all-electric is pretty groovy, though. 🙂 And I understand multi-zone from the hydronic systems is a very nice way to heat a coach. The Phaeton with Aqua Hot and heated flooring might be nice in the winter months. We have typically winterized our fiver...and said goodbye to it sometime in November...and hello sometime in late March. Hoping the motorhome will have us camping all year long. But...while I do have covered storage (storage facility with bays that provide roof, side walls, and back wall and open in the front), it isn't heated...so I'd have to re-winterize after each winter trip...and have read that winterizing with a hydronic system takes longer...and I can't used compressed air like I do now with my fiver. Looks like I have some more reading to do.

[DSDP_Don]

We have the Oasis system in our coach. It heats while driving, off of diesel and has two electric elements (30/50 amp). On mine, the upgrade to engine block heating is an additional switch and a pump. The connections, both wiring and plumbing, are already there. You might check to see if the AquaHot is upgradable.

With that said, these systems heat water so fast, you won't be waiting long for hot water, especially if you turn it on when you first stop. One of the guys on the Newmar forum just added the pump and switch to do engine preheat, but he lives back east. I think it's a nice feature, but out west, not necessary for us. The couple of times it got cold while on a trip, I just turn the block heater on the night before.

[dougrainer]

The 400 has NO engine preheat option or circuit. The 450D does and Tiffin does connect the Engine preheat on all their motorhomes that have the Engine preheat Aquahots. Doug
Note it states engine preheating---NO
MODEL 400D

Aqua-Hot’s 400-series are the Most Compact System for Diesel Motorhomes
Features
- Continuous on-demand hot water
- Quiet, clean, even, moist interior heat
- Adds thousands of dollars to the value of an RV
- Two sources of energy for heating comfort

- Uses AC shore power for light duty heating and hot water use
- Uses diesel fuel for heating in colder temperatures and continuous hot water
Specifications
- Maximum Interior Heat Exchanger BTUs 65,600
- Continuous, Tank-less Hot Water 1.25 GPM
- Engine Preheating No
- Electric Elements 1-120VAC, 1650W
- Fuel Diesel
- Max Fuel Usage .41 GPH
- AVG Fuel Usage /Day Dry Camping 1-4 Gallons
- AVG Fuel Usage/Day Shore Power 1-2 Gallons

[Bumpyroad]

mike brez wrote:
For cold starting the engine could it have a block heater?

Looks like you type faster

did you move to australia? seems your RV is upside down.
bumpy

[jorbill2or]

Mike and Trish wrote:

jorbill2or wrote:
The 400d can heat the engine ( thus the engine can heat the Aqua hot ) as an option ..its standard on the 450. Does tiffin not include that option ?

You might be right, but that's not the info I've seen. I have the 400D, and in looking through the manual, it appears that the only difference between it and the 450D is that the latter includes the engine loop. So if that's true, I don't see why there would be an "option" to add the engine loop to a 400D, because that would simply make it a 450D.

My last coach (a Mandalay) had a Hurricane hydronic heat system with the engine loop, and I admit I miss that feature for the ability to heat the coach and hot water using engine waste heat. But both coaches have also had an electric block heater, which I'm sure will be more than sufficient for its purpose. And as to Aqua-Hot (or other hydronic system) vs. a propane furnace and water heater -- worth every extra penny you pay, in my opinion. I'll never have another coach without one.

Perhaps your right that the " option " is the 450 I just remember reading somewhere the 400 had the option

[Mike_and_Trish]

jorbill2or wrote:
The 400d can heat the engine ( thus the engine can heat the Aqua hot ) as an option ..its standard on the 450. Does tiffin not include that option ?

You might be right, but that's not the info I've seen. I have the 400D, and in looking through the manual, it appears that the only difference between it and the 450D is that the latter includes the engine loop. So if that's true, I don't see why there would be an "option" to add the engine loop to a 400D, because that would simply make it a 450D.

My last coach (a Mandalay) had a Hurricane hydronic heat system with the engine loop, and I admit I miss that feature for the ability to heat the coach and hot water using engine waste heat. But both coaches have also had an electric block heater, which I'm sure will be more than sufficient for its purpose. And as to Aqua-Hot (or other hydronic system) vs. a propane furnace and water heater -- worth every extra penny you pay, in my opinion. I'll never have another coach without one.