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Another Aqua Hot question

April 17, 2018, 07:37:13 pm

My AH works great! In Texas. But up here in Utah it doesn't work so good. It warms the cabin just fine but the water is lukewarm, not a pleasant shower. My fluid level in the overflow bottle is low, but not much lower than last year when I opened the AH tank and put my finger in and found the anti-freeze level topped off. So I'm wondering whether the AH capacity is maxed out by heating the cabin, it is in the 30-40s daytime and below freezing nighttime? Should I just turn off cabin heat and try the water temp? How long to leave cabin heat off before checking water temp? Last time I had this problem BTW, yeah it was January 17.

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Re: Another Aqua Hot question

Reply #1 – April 17, 2018, 08:03:09 pm

At 30-40 degrees the electric side of the AH will keep up if your heating demands aren't too great.  Maybe 66 or 67 in the LR. The recovery time is slow and while it may feel like it is warming the LR the water will not be too warm.  Both use the same heat source (hot coolant).  When it gets that cold turn on the diesel burner as well.  Much more heat from it.  Make sure the basement wet bay thermostat is set right somthat it isn't on all the time.

If hot water still isn't there (120 degrees is what the mixing valve does) then you may have a mixing valve issue or a hot water restriction.  Is all of the hot water at all of the faucets and shower not hot enough? 

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Re: Another Aqua Hot question

Reply #2 – April 17, 2018, 08:40:45 pm

Had this issue with friends CC and his heating was limited inside but water was pretty hot. I found the check valve at tank was not holding water from returning to tank so it was poor flow thru the lines to radiators. Took the whole inside coach lines out as thought it was a blocked line but they were good. Finally took the check valve off and replaced it with another one and things worked well. I also replaced one of the flow pumps as I thought it was getting weak. The 2 things got system back to normal. By the way the old square flow pump that I replaced was actually corroding away (the plastic impeller and body of pump) and  glad I replaced it then.
Glad I do not have this system, lots of expensive parts.
JohnH

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Re: Another Aqua Hot question

Reply #3 – April 17, 2018, 09:05:02 pm

You didn't say if you are using diesel or electric. The diesel will keep the water hot and the coach warm in 0 deg. if working properly.

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Reply #4 – April 17, 2018, 09:08:50 pm

Thanks for the replies. I turned off cabin heat for about 30 minutes and turned on diesel AH. It took about 40 minutes or so but I did get hot water. Then turned cabin heat back on, waited 15 minutes or so and still got hot water. So yes it appears as though conditions here too much for ellec AH alone. Thanks again.

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Re: Another Aqua Hot question

Reply #5 – April 17, 2018, 09:20:41 pm

The water heating spec for the Aqua Hot heater is 55 degree temp rise at 1.5 gal per minute flow.  In cold climes, you may be ingesting really cold ground water such as perhaps 40 degrees.  Add 55 to that and you are not happy but the heater is working correctly.

So one can fill the onboard fresh water tank, turn the basement thermostat up to full hot and leave overnight.  Next morning you have warm enough water via the fresh water pump to have a nice shower.  You can possibly slow the water flow down giving it more time to pick up heat as long as you enjoy the show flow.

Keep the fresh water tank topped off as adding 20 gallons of cold to 80 that is warm works better than the other way around.  Electric is not rated to provide hot water for showers.  You always need the diesel burner and electric element if plugged in.  Diesel burner is needed in temps below 45 degrees for interior heating as well as hot water.

There could be a mixing valve issue as mentioned also.  To test, turn hot water on till it is just warm or cool.  Place your hand on the pipe from the tank to the mixing valve.  If real hot, mixing valve.  If not real hot, incoming water temp and/or to fast water flow.  You must be at the heater reaching under or around the burner to do this test.

Hope this helps.

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Reply #6 – April 18, 2018, 08:41:10 am

Flow rate is also important.  Switching to an Oxygenics shower head can make a real difference with cold city water conditions.

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Reply #7 – April 18, 2018, 10:25:43 pm

Thanks for the help. AH working well now.

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