AquaHot Temp Control Question

[Zmax73]

2001 H345 Vantare- How does the hot water temp get adjusted ? Mine has a AquaHot Bay control dial , but don`t know for sure if that does it? Also have a thermostat in the stateroom underneath the Cruisair control panel, wondering if that controls the Aquahot heating of the stateroom if needed ? Also curious how the Aquahot system switches between electric & diesel fired? Haven`t found a stand alone seperate electric water heater, but may be one hidden deep in them indiana jones caves ? Thanks for any help.9042

[jack14r]

The controls in your picture control the bay temperature not the aqua hot temperature,with a aqua hot you do not need a conventional water heater,I do not know if the water temperature is adjustable but check the web site or your owners documents.

[Larry W]

The hot water temp on the aqua hots I have had was adjustable. It is some what a hit and miss deal for one person. Remove the aqua hot cover and look for the cold water supply line. There is a tee in the line. At the tee one leg goes to the heat exchanger inside the boiler. The other leg of the tee goes to a valve that controls the amount of cold water that goes into the hot water outlet. The position on this valve controls the hot water temp. The amount of cold water mixed with the hot water controls the temp of the hot water. It took me a number of adjustments to get the water right for the better half.

[Zmax73]

Well looks like a project but need to learn. Thanks Larry ,I`ll give it a shot!

[Zmax73]

The electric heater thermostat shown heats the bay also, wonder why their`s two bay heaters then?

[jack14r]

There are 2 bay heaters so if you have the aqua hot turned off you can heat with electric heat or vice versa,our coaches have back up systems.

[Zmax73]

Ok, that sounds resonable. Tks Jack.

[RussWhite]

Here is a picture of the temperature controlled mixing valve on my AquaHot. I wanted the potable water a little hotter. I removed the burner/pump assembly for better access. The red marks are the factory setting and you can see I adjusted it from there. I think what you see there was about 5 degrees. It was a little difficult to turn, but once it moved it was not too bad. Don't know if this is what you are thining about, but pass it along in hopes it help someone.
Russ - Newell

[BenC]

2001 H345 Vantare- How does the hot water temp get adjusted ? Mine has a AquaHot Bay control dial , but don`t know for sure if that does it? Also have a thermostat in the stateroom underneath the Cruisair control panel, wondering if that controls the Aquahot heating of the stateroom if needed ? Also curious how the Aquahot system switches between electric & diesel fired? Haven`t found a stand alone seperate electric water heater, but may be one hidden deep in them indiana jones caves ? Thanks for any help.9042

The Aqua Hot system does not actually switch between diesel and electric, that is user controllable by turning on the Electric element or the Diesel Heat switch. Both sources heat the coolant in the unit AND the domestic hot water. The system contains a multi coil heat exchanger to simultaneously heat both the coolant that flows to the heat exchangers via the 3 zone pumps and a 6-gallon "slug" of dometic water in the coil box. If both independant sources of heat are turned ON, the control temperature for the 120v electric element is set higher than that of the diesel burner, so if the 120v electric element can keep up with demand, the diesel burner will not fire and heat the coolant mixture. Also, if you are driving down the road, there is a "motor aid" loop will heat the water above both the 120v electric control setpoint AND that of the diesel burner control thermostat, so neither other heat source will be on and "actively" heating the coolant in the Aqua Hot system.
With the Aqua Hot system, there is no need for a separate 120v water heater, so you will not find one in the "bowels" of your coach lol.
Vantare and others who installed the Aqua Hot system generally put separate 120v electric heaters for freeze protection, especially during storage of the coach. There is one in the plumbing bay, and any other storage compartment that may contain water lines, and toekick electric heaters in the bathroom, sometimes bedroom (depending on the converter), and also sometimes in the Salon &/or Galley area as well. These are all separate and redundant of the main heating system for customer convenience.
The mixing valve, described in a previous post is factory set to supply infinite 125-degree water to the hot water faucets. Adjusting this valve can result in hotter water, but usually customers who change this setting find the also "run out" of hot water during long showers because the heat exchanger is making the water hotter, is also cannot keep up with a prolonged demand for this higher enthalpy fluid output. The heat exchanger is only capable of transfering so much thermal energy, as is the burner only capable of producing a certain amount of thermal energy be transfered out through the coils into the domestic water system, based on time (flow rate) in contact with the coil walls.
Hope this helps.

[Zmax73]

Where is the Electric element & the Diesel Heat switch located ? So what should be adjusted to increase the water temp to prevent the running out of hot water while connected to shore pwr? Also what is the additional thermosat unit for in the states room underneath the cruiseair heating/ cooling panel ?
thanks Ben!!

[Zmax73]

Tks Russ. Did that increase the quantity of hot water ?

[RussWhite]

No - It has no effect on quantity. The quantity of heated water is what the heat exchanger inside the AquaHot holds. About six gallons I think. Those six gallons are heated to about 200 degrees according to my temperature readout. That is too hot to use directly, so there is a mixing valve that adds cold water to make the water that runs for household use. That is the valve I adjusted to make the water a bit hotter. In my case, not for the shower as it was already hot enough there and the shower has a temperature controlled mixing valve as well, but for washing dishes. I went back to my notes and found that before I adjsuted the mixing valve the hot water to my sink was 110 degrees and after adjustment 117 degrees.
I have two roughly 2500 watt 120vac heaters, one per phase as well as the diesel burner. I have as yet not managed to run out of hot water with both systems active.
From information given by a previous poster it sounds like my mixing valve may have been set a little low either from the factory or a previous owner The AquaHot is one of my favorite features after having propane heat and 10 gallons of hot water in my previous motor home. Good Luck! Russ

[JIM CHALOUPKA]

Russ, if you feel like going that extra bit, 120 deg. is recommended hygienically as the temperature for hot water.

Just sayin. JIM :)

[Jon Wehrenberg]

FWIW 115 degree water will scald a person. Having the water a little higher and then blending with some cold is OK because you cut down on the amount of HW that you draw from your HW heater.