Aqua Hot: Pros and Cons?

[docj]

Originally Posted by Moxy

there is no disputing that starting a stone cold engine at 20F is hard on it, if you don't think so read up on it, the AH warms the entire engine oil flows faster and freely when the engine is warm.

I did read up on it and here is what Caterpillar says about starting its engines down to 15 degrees. Notice that at altitudes up to 1500 ft there are no recommended procedures to follow and above 1500 only certain models require any assistance. Coolant heaters are optional below 15 degrees down to zero degrees F and are recommended at temps below that. I have no intention of being anywhere where it is below 15 degrees.

The entire Caterpillar cold weather starting guide can be found here https://safety.cat.com/cda/files/715...l+Machines.pdf

Sometimes the things we think we all know aren't always correct.

[Denali]

Originally Posted by glennb100

...Meanwhile, the fans in the heat exchangers are blowing. They have very noisy motors. On a cold night this repeats many times resulting in lots of noise and little sleep....

One poster said the fluid is "GRAS" and not antifreeze. That's not correct. GRAS is an abbreviation used by the FDA that stands for "Generally Recognized As Safe". That's FDA speak that the components of the mix are (relatively) non-toxic. GRAS can be used to describe many different formulations for many different applications.

Regarding noisy heat exchangers, you might want to check to see if Monaco used Aqua‐Hot Cozy Heat exchangers or HeaterCraft units. They used HeaterCraft exchangers in our coach, and I have replaced three of them with Cozy Heat units simply because the HeaterCraft exchangers were too noisy to use while we were sleeping.

What I said in an earlier post was that Aqua-Hot now uses "GRAS boiler anitfreeze". That's the propylene glycol used for at least ten years now in these units, although I read a post recently on Roger Berke's hydronic heating forum referring to yet another type of coolant that Aqua-Hot is using these days.

[smlranger]

Interesting that some folks want to try and talk someone into avoiding the Aqua Hot or, for that matter, an LP furnace. I think an honest discussion about the differences in the two is best and let the buyer decide. When we were shopping for a replacement for our 2002 DP, we knew little about Aqua Hot units and it was not a requirement for us. However, now that we have one, we like it and think it has advantages over LP furnaces and water heaters.

To the comment about the diesel exhaust exiting near a bedroom window, yes that is true on many rigs.... including ours. However, we are smart enough to not open a window near that exhaust. I did notice recently that Winnebago is having the exhaust exit at the rear of their Tour's and Ellipse models. That certainly is a better option.

Like everything else on these often complicated beasts, the Aqua Hot needs to be serviced properly. Roger Berke suggests the very best Alsayou can do is use it regularly. Those that are used infrequently and/or not serviced annually are those that give problems.

Also agree on the noise from the heat exchangers. My coach had the Heater Craft exchangers installed and the fans in those were just too noisy for us. I replaced all but the one under the dash with the quieter fans from Aqua Hot Cozy units. You can barely hear them run and they certainly do not keep us awake.

Bottom line for me, if I was looking for another coach, I would not hesitate to get another with an Aqua Hot but would not reject an otherwise good coach without one.

[Papa_Jim]

Great thread. I've learned a lot.

Our coach has a propane furnace mid-ship. The heat distribution is terrible. Hot in the middle of the coach, freezing up front, no matter how I've played around with the heat hosing. Very very noisy. We installed a brand new furnace last year, which works fine, but it's no better as far as heat distribution and noise is concerned.

So, I had decided that when we decided to buy our next coach, it would have aqua hot. Now, I know that I had better inspect it for noise and heat distribution.

Jim

[ISM500]

Originally Posted by Moxy

I think the arbitrary statistics are being quoted by the nay sayers, there are 1000's of aquahots in service, there are not 1000's of complaints in fact the vast majority work just fine for years,

Do you even bother to read what you write???

my cummins would be very expensive to replace as well, there have been reported problems regarding them too, should we now avoid cummins engines?

Who said anything about avoiding anything??

as far as the BMW comparison, if ya cant pay you shouldn't play,

Yet another leap in logic. I did not say anything about "can't pay". I am doing quite well, thank you.

my 850 alpina is worth every penny of the exorbitant cost for parts and service, same would apply to my aqua hot

FINALLY!!! An admission that the cost maybe "exorbitant". Your word not mine

Moxy

We have a saying in western Canada: You can always tell somebody from Ontario BUT you can't tell them much.

[Jbmsr]

Man I love my aqua hot. Used it for two years with no problems at all.
My unit runs quiet inside and out. I would like to be able to heat the system with electric instead of diesel when hooked up to a site. Although it's actually not bad on diesel.
Jesse

[Moxy]

Originally Posted by ISM500

We have a saying in western Canada: You can always tell somebody from Ontario BUT you can't tell them much.

that's brilliant, did you bother to read your posts, never mind all the others,

you referred to statistics not me, ignore everyone else's comments and here what it cost to fix the thing, and if somebody doesn't agree, it must be because they are from Ontario, do as I say not as I do.

" What he said! Some other parts that could be involved: mixing valve $165, circuit board $400, circulating pump (one per zone)$390-$900, burner assembly $3225 plus numerous electrical sensors.

Don't be bullied by those who try to minimize the downside by attempting to discredit anyone who does not share their views and quoting arbitrary statistics about satisfied owners."

several have made posts that would lead a reasonable person to think they should avoid an AH

"I would not buy another coach with one of these units in it"

"Unless you have more than two people and are travelling a lot I feel the Aqua Hot system is a waste--Hard to find dealers that can work on it--constant need of repair, too many parts, takes up storage space--give me the 10 gal water heater -(-never ran out of hot water in my other coach) Aqua Hot is nice IF it works, but be ready for maintenance galore!!"

do you always talk out of both sides of your mouth or is the a western thing

and there are certainly more

The cars, really, you brought them up, don't buy a 100,000 - 1,000,000 motorhome if you are not prepared to pay for repairs and maintenance, if repairs will break you then you are in over your head, and again you complained about the cost of a tire, what will you do if something serious goes south on your 6,

I admit, cars, motorcycles, motorhomes and boats are expensive, I have them all, I don't whine and complain about the cost, and the point was if ya cant pay don't play, simple concept, if its not an aqua hot in a coach, it will be something else, because they break down, sometimes its expensive, sometimes it is really expensive, rarely is it free,

so inclosing, yes I am from Ontario, clearly you are not, we don't have any saying about the Canadians from the West, in your case if I cant say anything nice, well you might know the rest, if not look it up.

Moxy

[StevenNSteph]

Originally Posted by Moxy

two people taking a reasonable shower will drain a 10 gallon electric or propane tank in a few minutes, so you can have a quicky shower or the second person showering better like cold showers,

I decided to test this just to make sure I wasn't imagining things. Full 10 gallon tank of hot water. Started the shower and started the timer when the water was at shower temperature. 19 minutes later, with the shower on full blast, it finally began to get cool. BTW, I don't have a tiny showerhead either, my SO likes lot's of hot water cascading through her hair washing out the shampoo and conditioners.

According to this website (http://www.home-water-works.org/indoor-use/showers) the average shower takes 8.2 minutes. I know I take quick showers 5 minutes or so and my SO takes long showers 15 minutes or so. When she showers I generally do the dishes and many times we have the washer running since that is our morning routine. She finishes and I go in and with the exception of one time I have never run out of hot water in 2 years of full-timing. (Remember the Hot water heater is heating water while you are using it so there is a bit of refresh time from when she exits the shower and I enter but never more than 10 minutes.)

So you two must take some pretty long showers to run out of water.

As far as the comparisons of aqua-hot's diesel use to that of propane use, I think this is a non-starter. All three of my non-aqua hot class A coaches had electric heat pumps and electric water heaters. I don't use any propane when I'm hooked up at a campground. All electric is cheaper so that is something to consider.

[Traps90]

Well we have had both, and will say as far as hot water goes, it's not a deal breaker either way. But when it comes to heating the coach, there is no comparison as far as we're concerned. The aquahot is waaaaaaaaaaaaaaaay better. Has nicer more uniform heat. We find it to be quitter.

[Pusherpilot]

Originally Posted by docj

I'm not sure why you need a long warmup period anyway. My C-12 doesn't even have glow plugs and starts just fine at 20 degrees. Its "cold start" fast idle lasts <2 minutes and then she's ready to roll. To my knowledge neither CAT nor Cummins recommends idling for more than a couple of minutes when cold.

Starting isn't the issue, wear both idling and under load during cold running is. The introduction of 5w40 oils has mitigated that. I don't like to have the trans moving the coach while it's still frozen either. Idling about 5 min after preheating the engine usually gets the trans into the 70 degree range. Fortunately I don't have that many cold starts to contend with. I have 100k plus miles on mine now and i need to get another 50-60k out of it before I'm done so I need to keep it out of the shop fer sure.
Ron

[docj]

Originally Posted by Pusherpilot

Starting isn't the issue, wear both idling and under load during cold running is. The introduction of 5w40 oils has mitigated that. I don't like to have the trans moving the coach while it's still frozen either. Idling about 5 min after preheating the engine usually gets the trans into the 70 degree range. Fortunately I don't have that many cold starts to contend with. I have 100k plus miles on mine now and i need to get another 50-60k out of it before I'm done so I need to keep it out of the shop fer sure.
Ron

Not to belabor this discussion, but every authoritative source (meaning one associated with an engine or vehicle manufacturer and not an internet forum) I can find says that engines operated at low speed and light load will warm up faster than engines that are simply idling. The following is taken from the Bluebird bus operating manual (school buses) and is typical of most:

Once a normal engine oil pressure and air pressure are reached, the vehicle may be operated at a light load and speed.

This is consistent with everything I have ever read about engines, both gas and diesel. Idling is not beneficial to any engine and is unnecessary in most circumstances.

The one thing that engine manufacturers are adamant about is not starting and stopping the engine in cold weather unless it is brought up to at least 180 degrees.

[Moxy]

Originally Posted by StevenNSteph

I decided to test this just to make sure I wasn't imagining things. Full 10 gallon tank of hot water. Started the shower and started the timer when the water was at shower temperature. 19 minutes later, with the shower on full blast, it finally began to get cool. BTW, I don't have a tiny showerhead either, my SO likes lot's of hot water cascading through her hair washing out the shampoo and conditioners.

According to this website (Showers | Home Water Works) the average shower takes 8.2 minutes. I know I take quick showers 5 minutes or so and my SO takes long showers 15 minutes or so. When she showers I generally do the dishes and many times we have the washer running since that is our morning routine. She finishes and I go in and with the exception of one time I have never run out of hot water in 2 years of full-timing. (Remember the Hot water heater is heating water while you are using it so there is a bit of refresh time from when she exits the shower and I enter but never more than 10 minutes.)

So you two must take some pretty long showers to run out of water.

As far as the comparisons of aqua-hot's diesel use to that of propane use, I think this is a non-starter. All three of my non-aqua hot class A coaches had electric heat pumps and electric water heaters. I don't use any propane when I'm hooked up at a campground. All electric is cheaper so that is something to consider.

sounds about right to me, In an average home, showers are typically the third largest water use after toilets and clothes washers. The average American shower uses 17.2 gallons (65.1 liters) and lasts for 8.2 minutes at average flow rate of 2.1 gallons per minute (gpm) (7.9 lpm).

so, I take likely 10 minute shower, run it for a few seconds then the wife usually a little longer and of coarse daughter about the same, I always used to go last in case we ran out, which we always did about half way through my shower, looking at the numbers Im lucky to get started, not sure what the ratio is but we like a hot shower

PDH online says multiply the result by the ratio of hot water to cold water used to determine your ... Generally, hot water is mixed with around 30-40%cold water in the shower. or 60 - 70 percent is hot water

so if my calculator works with your numbers three showers for us demands 57 gallons of water over 30 minutes approx to meet that demand according to the experts I would need more than 30 gallons of hot water minimum, even of there are just two of us that is 20 gallons of hot water, which the propane 10 gallon (most are 6) can not keep up with,

maybe you can squeak out two showers out of a 10 gallon water heater, good luck, I shave with hot water and don't want to have to worry about the next shower or running out in the middle of one, so Il stick with the aqua hot,

6 gallon propane water heater looks to be able to supply 10.5 gallons per hour of hot water so 10 gallon would be 15-16 gph of hot water, not a lot of reserve there for one shower, never mind three and maybe the dishes or a shave

Moxy

[gleydagatf]

Agree with all the above and love my AquaHot in my '03 Monaco Dynasty. One thing I've found is that smell or rough burning as detected at the exhaust pipe can be controlled by changing the fuel filter (a 15 minute job) often or when such a situation presents. (At least every 6 mo for full-timers). Quality of diesel fuel will also dictate timing. Aqua-Hot Heating Systems for RV, UTV, RTV is a great source of info and help.

[TrailerFool]

In this discussion of pros & cons I don't see any mention of whether or not there are any restrictions on the use of a diesel burner at ANY parks. Are there any? I do know that some places have idling restrictions, and we do dry camp (mostly at state and federal parks) periodically, so I'm wondering. Diesel burner systems certainly appear very appealing, but I'd like to know that their use isn't prohibited at any campgrounds before I buy a coach equipped with one.