Aqua Hot ?

[brobox]

Originally Posted by Crippsfl

The burner is your primary heat source for the Aqua hot. If the burner is in the on position, the unit will call for it even if you are on shore power and the electric switch is on. Although the system is an "insta-hot" type system, it does keep an exchanger at a temperature so that you have hot water instantly. When you do not use water, the unit keep this small amount ready. So you will hear the burner kick in even when you are not using water.

When I am plugged into 50 amp, I leave the burner off and use the electric switch on. If I know I am going to use more hot water (DW, long shower, or Clothes washer) I will put the diesel burner switch to on.

X2 I have heard my burner fire off many times while plugged into 50 amp, no furnace on, no water being used but burning diesel for no reason.

[Steve Ownby]

Originally Posted by brobox

X2 I have heard my burner fire off many times while plugged into 50 amp, no furnace on, no water being used but burning diesel for no reason.

Think of that big AH cabinet just as you would a residential water heater. The unit is pretty well insulated but, even with no usage the temp of the boiler fluid will drop until the control thermostat calls for input. Then which ever source you have selected, or both, will start putting heat into that fluid.

My AH is an older model equivalent to the current 600 series. It had only one electric element but two separate control thermostats. One for the burner and one for the electric. The electric thermostat was set to come on about 10 degrees above the burner. That makes it simple for me. I leave both on 24/7. If only light usage the electric keeps the boiler fluid above the control temp of the burner thermostat. My semi regular long shower will kick off the burner but otherwise the electric keeps it up to temp. For what ever reason, AH started using just one thermostat for both heat sources.


Steve Ownby
Full time since '07

[MRUSA14]

X2. Crippsfl you are learning fast!

[brobox]

Good explanation Steve. It was explained to me (but that hasn't been the truth many times) that with both switches on, electric "always" had preference and diesel would come on only if electric could not supply the needs, such as showers. But as we sat in our coach with noting being used, we could hear the burner firing for no reason unless it was the water cooling off, but I thought electric was suppose to keep up with that?

[brobox]

Originally Posted by MRUSA14

X2. Crippsfl you are learning fast!

Marc, your instruction sheet you posted awhile back has been a Bible to me. Thank you!!! Maybe you could post it again for the number of new AH users.

[pasdad1]

Originally Posted by Steve Ownby

For what ever reason, AH started using just one thermostat for both heat sources

I wonder if they found most aquahot users weren't using the diesel burner enough to keep it operating trouble free ....so decided to "force" the system to use it periodically, to "exercise it" ?

[MRUSA14]

Did you mean this one?

I think that people are getting confused by the various heating modes, particularly the Aquahot, so I would like to state some things that may not be obvious to those who have not had Aquahot before.

There are two things that you must set on the Aquahot. The first thing is what you want heated and how much. You do that by setting the thermostat to the gas setting for whatever zone or zones you want heated . There are 4 zones. Zone 1 is the front of the coach, Zone 2 is the in-floor heat, and Zone 3 on the main thermostat is the rear of the coach. The 4th zone is the basement, controlled by the basement thermostat. To heat with Aquahot, you set the temperature on each of these zones as desired. Zones 1-3 must be set on gas heat for Aquahot heating. The basement thermostat has only a temperature and off setting and always gets its heat from Aquahot. In addition to these 4 temperature zones, there is the engine heat switch which sends Aquahot heat to the engine block for pre-heating. This should be off at all times except when you wish to pre-heat your engine prior to starting, and is needed only in very cold temperatures.

The second thing you must do is select the heat source for the Aquahot. There are three ways to heat the water in the Aquahot. First off, on Anthem and Cornerstone (not Aspire) there is free heat that comes into the Aquahot any time your engine is running. This is automatic and does not need to be selected. The second heat source is the electric heat switch located near your thermostat. This will heat the Aquahot boiler from an electric shore power connection. The amount of heat available in this mode is small in relation to the heat available from the third source, which is the burner in the Aquahot. The burner runs on propane in the Aspire and diesel in the Anthem and Cornerstone. So, if (and only if) engine heat or electric (shorepower) heat is either not available or insufficient, you will need to turn on the Burner switch.

Use of the fireplace can heat the coach also, but I would not advise doing this without shorepower, as it is a very inefficient heat source if you must run the generator to use it. Better to use the Aquahot when not plugged in.

Lastly, there are the heat pumps. These are the rooftop Air Conditioners, running in reverse to heat the coach instead of cooling it. These also should be run on shore power and not on generator, as they are not as powerful as the Aquahot and are costly to run on generator. The heat pumps are ineffective at lower temperatures. They begin to lose efficiency when the temps gets down to 45F and they will stop heating altogether by the time the temperature gets to 40F or lower. You select the heat pumps by selecting electric heat on your main thermostat. They are very useful when you have a 50A hookup and the weather is above 40F, as they allow you to heat with the shorepower hookup instead of burning propane or diesel fuel.

So to recap, you can heat from
A. Fireplace
B. Heat Pumps

Both the above require shore power

or C. Aquahot
Aquahot requires a heat source (either electric or burner) to be selected, EXCEPT on Anthem and Cornerstone when the engine is running. On Anthem and Cornerstone, Engine heat is automatically sent to the Aquahot when available.

[Dr4Film]

Originally Posted by lp5151

I am noticing that we have hot water when we arrive at our campsite/rv park. we have an aqua hot diesel in our 2012 Anthem.

my question is, how can I have hot water when none of the system/switches are on.....is the engine loop and aqua hot always circulating and producing hot water, even though the switch is not in the on position? of course, the hot water does not last unless I switch on the electric and/or diesel switches. I thought the engine switch of the aqua hot only circulated fluid through the engine block when the switch was in the on position?

There are many different Aqua-Hot models with a variety of different controls depending on the model you own.

My reconditioned Aqua-Hot is model 431/12. For the Motor-Aide engine loop to heat up the Aqua-Hot coolant while driving I have to turn my Engine Pre-Heat dash switch to ON. That turns on a pump which allows the Cummins engine coolant line to circulate through the Aqua-Hot coolant tank keeping it hot.

If that switch is turned off, then my Webasto burner will come on while driving to keep the AH tank coolant hot.

Again every AH model operates differently. With mine I can leave the Electric assist switch and the Websato burner switch on 24/7. Under normal operation they never get turned off. During the summertime when the electric assist is often plenty to keep me supplied with hot water, I will turn off the Electric Assist switch to force the Webasto burner to work for a couple of days just to keep it exercised and keep the diesel nozzle from getting clogged up with junk.

Remember that every model is different so it is important to learn how your specific model operates and run it appropriately.

Another suggestion is to join the Hydronic Heating Forum run by Roger Berke. He can help answer any question or problem you may have with your model. He is one of the country's leading Aqua-Hot Technician's.

Dr4Film ----- Richard

[Crippsfl]

Originally Posted by MRUSA14

X2. Crippsfl you are learning fast!

What is they say about old dogs and new tricks??

[brobox]

That's the one Marc. I hope new AH owners will benefit from it as much as I did trying to learn how to use the heat functions. I know it's the wrong time of the year now, but I have copies everywhere when it's needed again.