Aqua-Hot Radiant Heat ? Too Expensive

We have been wintering in Mesa, AZ our first, and last, visit to this beautiful part of the country ? it?s just been too darn cold.  So next winter its back to central Florida with their humidity and bugs, warm does matter. 

So here is the issue, we have been running the Aqua-Hot system as our primary heat source for approximately 6 weeks.  For one week the temps would plunge to the mid 20?s at nite and reach, maybe, the 50?s during the day.  The remaining 5 weeks was 30?s nite, 50-60 during the day.  We have the coach thermostat set at 67 degrees.  Our Aqua-Hot system provides continuous hot water and a radiator system for heating the coach.  The model is AHE450DW3 and is called ?Hydronic Heat?.  It has a diesel burner which ignites on demand, we really like the hot water system and the heater puts out great heat.

But, Aqua-Hot is always sipping from the diesel fuel tank.  When only heating hot water for shower and sinks the diesel used is not noticeable, continuous use for heating the coach is a different story.  I started monitoring the fuel usage and after 6 weeks the fuel used was quite evident, we went back to heat pumps and the fake fireplace.

When we travel the roads we always fill up with the fuel gauge registering between ? full and ? full (it just seems less expensive that way).  Today we fueled up after running the Aqua-Hot system as the primary heat system for 6 weeks with no miles down the road, bad news, the tank registered less than ? full.  Now I?m doing some guess work here, I do not have perfect memory as to our fuel situation last October, but I think the Aqua-Hot system used about 50 gallons of diesel during the cold spell.  Instead of our normal 50 gallons at a fuel stop, today I pumped in 102 gallons, ouch.  50 gallons of diesel used to heat the coach equals $200.

So it?s back to the Sun Shine state to avoid, hopefully, cold winters and if heat is needed for long periods, I will stay away from the Aqua-Hot ?Hydronic Heater?.

Thanks for the great news Tom! I welcome your observations...always helpful to me.

I have heard some folks liked having the unit, but yours is the first report as to the cost of long term use. Thanks for the report Tom.

We are currently sitting in Huachuca City where the temp is 52. The current temp in Titusville, where we live, is 32! It gets cold in both places. I think you'll have to go further south for warmer weather.

And here in the Dallas Fort worth area today was 77.  Go figure.  The good thing about a MH is they're mobile, if it's under 50 degrees, it's time to get mobile.

Actually, that info is pretty informative Tom. Thanks. We've been looking at coaches for a few years now, and the one we like best has the same Aqua-Hot system (the 450). I have always been curious about its fuel-burn in"real-world" conditions. I know they're supposed to be much quieter than the typical propane furnaces like we have in our current MH, and like you said, they also heat the water. But this is the first time I've seen someone comment on the furnace's fuel efficiency.

Kev

We have a Hurricane hydronic heating system in our MH; the Hurricane is not as well known as the AquaHot (nor as expensive) but it does the same job.  My experience has been that if the temps get down to the 30's we will burn around a gallon of fuel overnight to stay warm.  Our burner is rated at 0.4 gals/hr of burner operation and it doesn't run more than a ~30% duty cycle because it heats the circulating liquid a lot faster than the heat can be transferred into the coach. 

Here at our winter location where we've been in place since Dec 1, I've purchased a 5 gal diesel can which I've used to put 40 gallons back into the tank over the past month. (~$160).  That may sound like a lot, but, by comparison my electric costs were only ~$40 last month because we weren't using electricity for heating.  There's no "free lunch", the energy for heating has to come from somewhere.  A benefit of a hydronic heating system is that it also provides unlimited hot water which my DW thinks is the best thing it does for us.

I don't think that's a lot of fuel for the amount of heat you obtained, but obviously using an electric alternative would use less of the onboard fuel. But if you were paying for the electricity by the KWH, you likely would have found that to be expensive as well. There is no free lunch, but if you have electric included in the site rent it would seem free, so that is always the most cost-effective method of heating.

Most Aquahot systems include an electric heater as well as the diesel burner. Doesn't yours?

Gary RV Roamer said:

I don't think that's a lot of fuel for the amount of heat you obtained, but obviously using an electric alternative would use less of the onboard fuel. But if you were paying for the electricity by the KWH, you likely would have found that to be expensive as well. There is no free lunch, but if you have electric included in the site rent it would seem free, so that is always the most cost-effective method of heating.

Most Aquahot systems include an electric heater as well as the diesel burner. Doesn't yours?

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It does Gary, but it has limited capacity, if you are using the electric only you run out of hot water quickly.

I realize heat costs regardless of source, with the current cost of diesel, $4.05 per gallon, it seems to me  electric is cheaper.  I will track my electric costs for the next month, we are currently in Tucson and looks like a cold week is headed our way low 50's days, low 30's nites.

I realize Florida has spurts of cold, but not as extended as we have experienced in AZ.

Every year is different, our winter in AZ it went down to -20.  Of course we were at the Grand Canyon.  Maybe just go further south in AZ?  Even with the colder temps, more comfy than the humidity in FL.

tomnnva said:

So here is the issue, we have been running the Aqua-Hot system as our primary heat source for approximately 6 weeks.

When we travel the roads we always fill up with the fuel gauge registering between ? full and ? full (it just seems less expensive that way).  Today we fueled up after running the Aqua-Hot system as the primary heat system for 6 weeks with no miles down the road, bad news, the tank registered less than ? full.  Now I?m doing some guess work here, I do not have perfect memory as to our fuel situation last October, but I think the Aqua-Hot system used about 50 gallons of diesel during the cold spell.  Instead of our normal 50 gallons at a fuel stop, today I pumped in 102 gallons, ouch.  50 gallons of diesel used to heat the coach equals $200.

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$200 for 6 weeks... $33/wk ...  BTW 50 gallons of diesel is equal to about 2100 Kw-Hr of electrical... or 350 Kw-Hr per week for 6 weeks.    That's a lot of electricity for a small "condo". 

Certainly an interesting story. But, the 50 gallons used is a guess as he doesn't really remember the fuel situation in October last year. Read the account carefully and see that there is a lot of guessing. And the alternative of using the heat pumps is an interesting theory since they only work down to a certain temperature, (humidity is a factor) before they freeze up and stop producing heat altogether. My system then automatically switches to the AquaHot system.

We used $137 of electricity in December in our park and used the AquaHot as auxilliary during the night. So, I guess you have to pay one way or the other. I'm having the time of my life traveling in the warm south each winter. If I have to eat a little lower on the hog for a few months when it's unusually cold then so be it. Fortunately we're not down to the feet yet, we're still at ribs and hams.

I'm very happy to stay in AZ without the bugs and humidity.

Ken

When we first got a coach with Aqua Hot (Hydro Hot) it was a 2000 Windsor that we picked up at the factory mid Oct. 1999. Our first stop was a work assignment in Springfield, MO from the beginning of November until the day before Christmas.  Seven weeks, definitely colder than Arizona. I estimated we used 22 to 25 gallons. I had filled up prior to going to the CG and at Joplin, Mo after leaving so I had a pretty good way to estimate the usage. Diesel was pretty cheap then so I though it was pretty cheap heat. Our Windsor was a single slide so I am sure our current coach (43ft 4 slides) would use more, but not that much more.

Here at Happy Trails (AZ) we rarely use the diesel. Normally we rely on the Aqua Hot electric and a small space heater.

ken

This is interesting. It has been an unusually cold winter here in AZ. I had planned to winter in Moab, Utah one of my favorite places in this world, but when it was -12 degrees and everything froze on my 5er, I decided it was time to move further South and have still hit cold weather, but not as cold as it would have been had I stayed in UT.

My electric for this past month was $100.00 which is primarily for heat! I am hoping that the worst of this cold weather is over, however, as I write this they are predicting a weekend of cold weather...but not terrible although the wind is howling now and I do have the electric heater on low.

Still beats the humidity and bugs in Florida...but I may winter further South in AZ next winter!

Jim

A negative with the aqua-hot is that it has a very high pitched irritating whine to it on the outside which can really upset the neighbors. We really wanted to stay away from it when we bought the new coach but do envy the continuous hot water supply of the aqua-hot.

>>A negative with the aqua-hot is that it has a very high pitched irritating whine to it on the outside which can really upset the neighbors. We really wanted to stay away from it when we bought the new coach but do envy the continuous hot water supply of the aqua-hot.<<


I do not find most to be bad. But I have heard some that are worse - louder. I suggest you call Aqua Hot and see what they say. Years ago I had a burner replaced by the then Vehicle Systems and the replacement had a loud high pitch whine. I called VS and they gave me instructions as to how to reduce the whine. I don't remember exactly what they said to try, but the burner had to be out of the unit. I do remember that it helped.

ken
'

It would be interesting to know what the folks camped next to you paid in propane cost to run there propane furnaces. We have spent the past six weeks camped just down the road in Fountain Hills,AZ and the propane truck is in the park every day. That said , we do very much like our diesel burner, and would never go back propane furnaces. It has been much colder than normal this year in AZ.

Our current location Tucson, AZ ? The Weather Channel App Tucson hi/low temperature forecast:
Sat 54/32, Sun 58/36, Mon 59/32, Tues 60/34, plus they have issued a winter weather advisory, snow possible.

Same App Titusville, Fl hi/low temperature forecast:
Sat 73/55, Sun 75/58, Mon 82/60, Tues 83/65

Bugs and humidity sound pretty good about now   Hello TGO?

Becks said:

It would be interesting to know what the folks camped next to you paid in propane cost to run there propane furnaces. We have spent the past six weeks camped just down the road in Fountain Hills,AZ and the propane truck is in the park every day. That said , we do very much like our diesel burner, and would never go back propane furnaces. It has been much colder than normal this year in AZ.

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That is an excellent point, we are staying at VDO in Mesa, will be returning there next week, and I also have seen a propane truck every day in the park.  I will ask some propane users on our return what they have been spending to keep warm.

Do you know the guy from Fountain Hills that won the big jackpot?

Right after we bought our place here in the Texas Hill Country (November '07), all of our furniture was in storage so we lived in the coach parked near the front of our house for about a month or two.  I ran 30 amp power figuring that would be plenty.

Then we had three days of below freezing weather, snow and sleet - the heat pump wouldn't work so we were on the propane furnace.  Even with the inside temp set to about 60 (65?) it was running 30 minutes out of every hour  ??? and after a few days of this we were literally burning through all of our 31 gallon tank.  There were no propane companies that would deliver to an RV and our gate was so small, I was afraid to try to exit through it since it took about 20 minutes of maneuvering when we brought the coach through it the first time.  Fortunately the weather warmed up before we ran out of propane (and we had a very wide gate installed first thing  8).)