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  • Can’t find the thermostat for our AquaHot

    Posted by Cor on April 14, 2014 at 6:45 am

    Greetings,

    We currently have our Prevost Marathon RV in front of our house with a problem in the engine’s ECU.

    We are looking to turn off the AquaHot boiler because we are affraid it will drain too much power from the batteries and in the manual we read that it’s a fuel heater (so it uses diesel) and we want to prevent that all the diesel will be used up by the AquaHot. But we can’t find the thermostat that controls the Aquahot. We have looked everywhere and as far as we can tell there is no control panel whatsoever labeled as AquaHot.

    Here are some pictures of the place where the AquaHot is installed in the RV, and a picture from the other side where all the plumbing and controls are.


    Could someone tell me where we could possible find the thermostat for the AquaHot, or where we can disable the AquaHot all together? We do not really need hot water right now in the RV since it is in front of our house and we don’t use it anyway.

    Archived replied 12 years, 6 months ago 4 Members · 8 Replies
  • 8 Replies
  • Archived

    Member
    April 14, 2014 at 7:21 am

    Turn off the 120v breaker at the electrical panel.

  • Archived

    Member
    April 14, 2014 at 7:26 am

    On my Royale there is a switch on the dash that turns off the burner and a switch under the sink that turns off the 120 volt heating element. There should also be a 12 volt breaker somewhere that controls 12 volt power to the Aqua Hot. If that breaker is turned off the diesel burner will not run.

  • Archived

    Member
    April 14, 2014 at 8:20 am

    Just so everyone is aware a Webasto or Aqua Hot may be diesel powered, but they also use a lot of electrical power also due to fans, pumps, etc.

  • Jim/Chris

    Member
    April 14, 2014 at 8:41 am

    I know on my Marathon all you have to do to turn
    off the Webasto is turn of the 12 Volt heat on the power panel. If that is not
    doable on you coach, remove the Aqua Hot cover there are four fuses on the side
    above the Webasto burner pull these fuses out the will disable the Aqua Hot.
    The other choice is to call Aqua Hot tech support good luck.

  • Archived

    Member
    April 14, 2014 at 9:24 am

    if your coach is a Marathon, and that’s what we discern from your sewer bay photo, and a Marathon having an Aquahot is unusual, have you checked to see if your 12v heat button or 12v hot water button in your bedroom switch/button panel is in off position? There could also be a button on your side dash/cockpit labeled “engine heat” or “engine pre heat”. If the side dash button is “on”, nothing else you find will turn it off. It would be very helpful if you listed your coach converter/year/model. Each converter has their way of doing things. My two cents.

  • Archived

    Member
    April 14, 2014 at 12:27 pm

    There is a switch inside the coach that turns the diesel burner on and off. Then diesel burner only runs when the control thermostat inside of the heater (not accessable by the owner) calls for heat. The diesel supply for the Aqua Hot only goes down 3/4 of the way in the diesel fuel tank so it can not run you completely out of fuel.

    When not needing interior or hot water heating, the switch can be turned off to save diesel fuel.

    The 120 vac circuit breaker has nothing to do with the operation of the diesel burner. The electric element on off switch which is also inside the coach turns the element on if the 120 vac cuircuit breaker is on. The element only turns on when the conrol thermostat (inside the heater like the diesel control thermostat) calls for heat. Both of these thermostats control the temp of the coolant in the Aqua Hot 16 gallon coolant tank.

    When the generator is off and the coach is not plugged into shorepower, the element can not be energized no matter what the switch settings unless the electric element can be powered through the inverter which is almost never wired that way by the coach manufacturer.

    Hope this helps,

    Trainer

  • Mark

    Member
    April 14, 2014 at 12:31 pm

    I wanted to add to my above post but could not edit my post for some reason.

    The interior fan coils only run when the interior thermostat is on, selected for Aqua Hot heating and calling for interior heat. When these thermostats are off, so are the fan coils.

    Trainer

  • Archived

    Member
    April 14, 2014 at 1:43 pm

    Maybe I misunderstand, but I think OP is worried about draining the chassis batteries while dealing with a ECM problem. My Aquahot has no connection to the chassis batteries and I suspect that the typical configuration is to run it exclusively from the house batteries. As others have posted, you should have no 12 volt draw as long as the burner is not set to run.

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