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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Virginia on November 27, 2010, 10:38:31 pm

Title: Better Understanding of Aqua Hot System
Post by: Virginia on November 27, 2010, 10:38:31 pm
Last night we went down to 27 - late afternoon prior to filled fresh water, downed city water intake, closed off dumb lines. Basement heat setting at 50.

With Aqua Hot working off electrical only, since in RV park - Woke very early to furnace just blowing air that was slightly warm/cool and not shutting off since not reaching temp setting. Flipped on the diesel switch for Aqua Hot to heat things up and after a little bit blower shut down once temp setting reached.

What gives here? My understanding not necessary to run off of both diesel and electric when connected to electric as it does not increase the heat of either water or furnace -
Title: Re: Better Understanding of Aqua Hot System
Post by: George Stoltz on November 27, 2010, 10:42:44 pm
Virginia,
 
Does the RV park not let you run your Aqua-Hot at night?  That would be very unusual. We set ours to run on both electric and diesel.
Title: Re: Better Understanding of Aqua Hot System
Post by: Barry Beam on November 27, 2010, 10:45:56 pm
Last night we went down to 27 - late afternoon prior to filled fresh water, downed city water intake, closed off dumb lines. Basement heat setting at 50.

With Aqua Hot working off electrical only, since in RV park - Woke very early to furnace just blowing air that was slightly warm/cool and not shutting off since not reaching temp setting. Flipped on the diesel switch for Aqua Hot to heat things up and after a little bit blower shut down once temp setting reached.

What gives here? My understanding not necessary to run off of both diesel and electric when connected to electric as it does not increase the heat of either water or furnace -
With temperatures that low, just using just electric it cannot keep up.
You must use the diesel which produces much more heat.
Normally you can have both turned on and the diesel will only come on if the electric element can not keep up with the demand.
http://beamalarm.com/Documents/aquahot_on_foretravel_rv.htm (http://beamalarm.com/Documents/aquahot_on_foretravel_rv.htm)
Title: Re: Better Understanding of Aqua Hot System
Post by: Virginia on November 27, 2010, 11:00:18 pm
Thank You Barry

We will be in lower temps on Tuesday evening again and I will set both diesel and electric after reading your web site info -

You actually made it more clear than any of the other info I've had  :)

Again, thank you very much
Title: Re: Better Understanding of Aqua Hot System
Post by: Michelle on November 27, 2010, 11:01:38 pm
Barry states it quite eloquently.

We have done fine on electric-only for showers, sinks, and Splendide.  But when heat is required and the heat-pump mode of the roof units can't keep up (anything below 34 or so, when the thermostats automagically switch from heat pump to furnace), diesel operation of the Aqua-hot is necessary.

Michelle
Title: Re: Better Understanding of Aqua Hot System
Post by: Barry Beam on November 27, 2010, 11:11:19 pm
Barry states it quite eloquently.
We have done fine on electric-only for showers, sinks, and Splendide. 
But when heat is required and the heat-pump mode of the roof units can't keep up (anything below 34 or so, when the thermostats automagically switch from heat pump to furnace), diesel operation of the Aqua-hot is necessary.
Michelle
That brings up a question I have thought about.
I have never used the heat pump. Is there any advantage to using it if you have an aquahot?
Also, are you saying if you are using the heat pump the "duo therm" will automatically switch to furnace setting (aquahot) if the temperature goes below 34 or so?
Title: Re: Better Understanding of Aqua Hot System
Post by: Virginia on November 27, 2010, 11:13:29 pm
George -
The Aqua Hot diesel noise is so low, if a RV park complained then IMHO I'd tell them to shove it - only generator's are limited in usage in rv parks, but I've not had problems with those either.

No, I was just under the impression did not need to have the diesel on when on electric, but in reading Barry's info, which is so clear and understandable over everything else I've gathered. I don't think the manual is as clear as Barry's - IMHO

... when heat is required and the heat-pump mode of the roof units can't keep up (anything below 34 or so, when the thermostats automatically switch from heat pump to furnace), diesel operation of the Aqua-hot is necessary.
Michelle

OK - Michelle - explain the Auto switching from Heat Pump to Furnace?
Title: Re: Better Understanding of Aqua Hot System
Post by: Michelle on November 27, 2010, 11:19:43 pm
That brings up a question I have thought about.
I have never used the heat pump. Is there any advantage to using it if you have an aquahot?

Diesel fuel savings.  Usually, electric is free (unless you are doing monthly or seasonal, and even then it depends upon the campground).  That's really the only advantage.  It's noisier, that's for sure.

Quote
Also, are you saying if you are using the heat pump the "duo therm" will automatically switch to furnace setting (aquahot) if the temperature goes below 34 or so?

That's our understanding and experience (one cold night in Santa Fe, NM).  I believe it's in the manual somewhere.

Also, if one of the two thermostats is set to "furnace", the other will not operate on "heat pump".  You cannot set them to be 2 different modes, at least in our experience, and I seem to recall "furnace" takes precedence (but don't quote me)

Michelle

Edited to add - it will NOT automatically turn on your Aqua-Hot when it switches, of course...
Title: Re: Better Understanding of Aqua Hot System
Post by: George Stoltz on November 27, 2010, 11:20:37 pm
George -
The Aqua Hot diesel noise is so low, if a RV park complained then IMHO I'd tell them to shove it - only generator's are limited in usage in rv parks, but I've not had problems with those either.

No, I was just under the impression did not need to have the diesel on when on electric, but in reading Barry's info, which is so clear and understandable over everything else I've gathered. I don't think the manual is as clear as Barry's - IMHO

I was trying to figure out why you did not have both the electric and diesel on at the same time.  You have learned so much about Foretravel that I did not even think it was a case of not knowing.  But, now we know.
Title: Re: Better Understanding of Aqua Hot System
Post by: Virginia on November 27, 2010, 11:35:25 pm
Well George - I won't tell where I got the "impression" on using electric only, but next time we see each other I will  ;) remind me  :))

I was really puzzled when got up this morning and heavy frost on pumpkin to that cool air blowing -

I've got a DeLonghi radiator style portable space heater which cuts the chill for us nicely - so besides the Heat Pumps we're not going to freeze - Also, have that bottle of Myer's Rum too  :))

Sure ain't gona freeze cause I'll just crank up ole Blue Eyes and shag further south - I'm allergic to anything under 50 degrees anyway  ;)
Title: Re: Better Understanding of Aqua Hot System
Post by: Mark and Tracy on November 27, 2010, 11:41:52 pm
Same thing happen to Tracy and I last night in Wimberley, tx....Outside temp dropped to 24 degs and Tracy woke me up telling me it was cold. I ran flipped the burner on and 30 min later everything was just fine....
Title: Re: Better Understanding of Aqua Hot System
Post by: Peter & Beth on November 27, 2010, 11:42:32 pm
Just as a learning experience for me as I do not have Aquahot...How do the bays get heat when only the heat pumps are selected?  Does the Aquahot indeed come on automatically at the bay thermostat preset?
Title: Re: Better Understanding of Aqua Hot System
Post by: Michelle on November 27, 2010, 11:53:15 pm
How do the bays get heat when only the heat pumps are selected?  Does the Aquahot indeed come on automatically at the bay thermostat preset?

They don't.  And nope.  If you think the temperatures are going to be low enough to need bay heat, you'd better have your Aquahot turned on.

Having it turned on doesn't mean that the interior thermostats are set for "furnace", only that the diesel and/or electric heat sources of the AH itself are on and heating or maintaining the AH fluid at the desired temperature.

You still have to enable a heat mode on the thermostats.
Title: Re: Better Understanding of Aqua Hot System
Post by: J. D. Stevens on November 28, 2010, 12:02:16 am
Some info on heat pumps, "auxiliary heat," and Duo-Therm Comfort Control Center is here. http://www.rvtechlibrary.com/heatair/DuoTherm_tstat_owners.pdf (http://www.rvtechlibrary.com/heatair/DuoTherm_tstat_owners.pdf)

The way I read it, it will shut down a heat pump if the outside ambient temperature drops below 30F. If a furnace is available, it will be turned on. Heat pumps cease to function properly at low ambient temperatures without special heaters. Our coach has propane furnaces and heat strips rather than Aqua-Hot and heat pumps.

Since the basement only gets heat from the propane furnaces, I expect we will always use the furnaces if the temperature is below 32F. We will probably try to use electric heat when we can in order to conserve propane. The conservation will be to avoid having to refill. We expect to learn a lot about keeping the coach warm soon. We plan to visit family in Missouri and Montana in December.
Title: Re: Better Understanding of Aqua Hot System
Post by: Peter & Beth on November 28, 2010, 12:09:51 am
JD,
If you have a source of shore power, then you can always add incandescent bulbs in both sides of the "water bay" compartment to supplement the propane furnace.  This as a stop gap measure should anything go wrong with the propane furnace.
Title: Re: Better Understanding of Aqua Hot System
Post by: Kent Speers on November 28, 2010, 12:19:13 am
We too have propane furnaces and we are in Kansas City right now. We use two 1500 watt electric heaters until the temps get below freezing then use the main furnace in the front of the coach to keep the bays heated. We set the front furnace thermostat at the bottom setting when the outside temps are down to 20 degrees and shut the door to the back of the coach. We use one of the electric heaters to heat the bathroom and bedroom. When the temps go above 32 during the day, we turn off the furnace and use electric heat throughout. When temps are below 20 we set the front/main furnace thermostat at 65 degrees to insure the bays stay warm enough.

We use the small electric heaters to avoid wear on the blower of our Domectic A/C's with heat strips. You can replace a 1500 watt heater for $50. A new A/C unit will cost $1,000.

By heating this way, we use very little propane. We could go for many weeks on one tank. However, be careful because if you are paying for your electricity, it may be more expensive than using the propane furnace.
Title: Re: Better Understanding of Aqua Hot System
Post by: John S on November 28, 2010, 06:56:14 am
The new aquahots have a dual electric heating element and you can heat the coach only on electric. The older ones with one electric element needs the diesel boiler to run to heat the coach and the engine too if you are going to leave out. I just turned my diesel on a hour ago when I realized it got too cold for only the electric element last night.  I have it running now and it is running full diesel right now to preheat the engine.  It also heated the inside of the coach much faster....
Title: Re: Better Understanding of Aqua Hot System
Post by: J. D. Stevens on November 28, 2010, 08:58:55 am
Peter, Beth, and Kent,

Thanks for the information particular to a coach with propane furnaces. It's good to hear that we can probably extend the time between refills even in cold weather.

I have on board three portable electric heaters with thermostatic controls. I have used one with satisfactory results. The two new ones are the same brand in a more compact form. I have a thermometer with four remote sensors. I plan to scatter the sensors around the bays and coach to monitor conditions.
Title: Re: Better Understanding of Aqua Hot System
Post by: Kent Speers on November 28, 2010, 09:14:51 am
JD, just remember that the front furnace supplies heat to the bays so when it's really cold outside, turn off the electric heater in the front and let the furnace do its work. By the way, where did you get a thermometer with 4 sensors? I like that idea.
Title: Re: Better Understanding of Aqua Hot System
Post by: Scott Beard on November 28, 2010, 12:31:29 pm
How do you heat the engine pre start in these cold conditions? 
Title: Re: Better Understanding of Aqua Hot System
Post by: Scott Beard on November 28, 2010, 12:36:30 pm
Just read Barry's very informative Aqua Hot section on his web site so please disregard Newbie Question above.  What would we all do without Barry!!
Title: Re: Better Understanding of Aqua Hot System
Post by: Peter & Beth on November 28, 2010, 12:44:03 pm
Scott,
I have no electric available in my storage facility, but here's what I do.
1.  Re-install the negative battery connections (coach & starting)
2.  Start genset.
3.  Turn engine block heater "on".
4.  Turn propane furnace "on" [to get the chill out of the coach inside]
5.  Turn "Boost" switch "on"
6.  Run this set up for 30 to 45 minnutes.
7.  Check amp draw at house batteries to ensure alternator is not taxed once diesel engine starts.
8.  Start engine.
9.  Turn block heater, boost switch "off"
 
Ready to go after air is at operating pressure and oil is beginning to warm up.
 
Title: Re: Better Understanding of Aqua Hot System
Post by: J. D. Stevens on November 28, 2010, 03:25:19 pm
Kent,

I just checked the bay vents on our 1997 U295 and found that the rear (bedroom, passenger side) furnace supplies air flow to the bays. There is a port in the service entrance bay, and one in the water heater/manifold bay. They blow air when the rear furnace operates, but not when the front furnace operates. It appears they are designed to protect the water tanks and plumbing when the rear furnace runs. Results may vary depending on the build of the coach.

I bought thermometers from Amazon. On reviewing literature, the unit will display local temperature and three remotes. I haven't gotten all the batteries required yet, so have not proven that my plan for monitoring bays will work. The thermometer is described at http://lacrossetechnology.com/9121/index.php. (http://lacrossetechnology.com/9121/index.php.)