Author Topic: Diesel Consumption Using Hydrohot for Water Only  (Read 11984 times)

Teresa Owen

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Diesel Consumption Using Hydrohot for Water Only
« on: December 19, 2014, 08:57:28 PM »
Can anyone give me an idea of how much diesel you use heating just water with the Hydrohot, i.e., a 1/2 gallon a day?   We won't be using it to heat the coach. Just using the electric to heat water isn't working for me.  I want to be able to wash hands and dishes with hot water, no showers.  Just curious, we are parked for 3 - 4 months and don't want to move the coach to get fuel for hot water.  Is it

Coach is 2004 Beaver Monterey

Thanks for your responses!

Teresa

Edward Buker

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #1 on: December 19, 2014, 09:21:57 PM »
It all depends on how much water is used and how cold the water is to begin with. The best way to know may be  to note how long the burner typically runs in a days time with your use and multiply that by about .4 gallons an hour. If you do not need the hot water during sleep time you may want to shut the burner off during the night and enable it in the morning.

Later Ed

David T. Richelderfer

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #2 on: December 19, 2014, 09:42:47 PM »
I assume you are or will be plugged in so that the electric element will be heating water.  If so, then just turn on the HydroHot/AquaHot and it will fire up the diesel heating of water when you have used enough for its thermostat to engage it.  Otherwise, the electric element will keep the water hot.

I am not intimately knowledgeable of the differences between the various models of HydroHots and AquaHots, but in my unit (an AquaHot) there are 4 different thermostats for the 2 water heating functions - those 2 functions being the electric element and diesel burner.  Each function has a thermostat for turning it on and another for turning it off.  The electric element's thermostats run about 10 degrees hotter than the diesel burner.  Sooooo... if the electric element is capable of keeping the water temperature above the diesel burner's turn-on temperature, then the diesel burner will never need to fire up.  Only when you use enough hot water to reduce the water temperature down to the diesel burner's turn-on temperature will its thermostat turn it on.  Otherise, in answer to your direct question as Mr. Buker said, your diesel burner will burn about 0.4 gallons per hour of burner time.

Does this make sense?  If I am not correct here, then I am sure others will chime in.
« Last Edit: December 19, 2014, 09:44:37 PM by David T. Richelderfer »
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Bob Jae

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #3 on: December 19, 2014, 10:38:12 PM »
I know on my Aqua Hot AHE-450-DE4 both the electric and diesel turn on at the same time if both switches are turned on.  Some models do have two thermostats and the diesel comes on if the electric can not keep up. 

It you are running out of hot water just washing your hands and dishes I would investigate other problems.  Perhaps the stir pump or mixing valve.

Check out the forums at http://rvhydronicheaterrepair.com Roger Berke is an expert on these.


Orman Claxton

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #4 on: December 20, 2014, 05:31:35 AM »
The Aqua-Hot will consume approx 1/3 gph running time, ie: running 3 full hours will consume approx. 1gallon diesel  8)

Bill Sprague

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #5 on: December 20, 2014, 04:07:40 PM »
I want to be able to wash hands and dishes with hot water, no showers. 
Teresa,
BJ and I have had our 04 Monterey for about a decade, lived in it full time for over 2 years and continue to use it about half of every year.  You should have no trouble washing hands and doing dishes with electric only.

I'm writing the rest of this assuming you leave the electric hot water switch on 24/7.   

We both use the shower daily.  Our habit is to turn on the diesel for the duration of the shower.  I can shower on electric only but am lazy, slow, not green, wasteful and like luxurious showers.  BJ finds getting the shampoo out of her hair takes long enough that an electric only shower is not a good idea. 

An important rationalization is that HydroHot maintenance costs will be a lot lower with regular use or "exercise".  If a little fuel doesn't flow through it frequently, things get clogged up, stuck or quit.

How much fuel does it take?  Orman is correct if it burns continuously.  Even in chilly weather, using it for cabin heat, it cycles on and off.   Mostly off. 

It is difficult to measure precise use but you can come very close.  Our diesel fuel gauge remains pointing to the quantity in the tank at engine shutdown.  The next time you turn the key, the needle will move to the current quantity.  If you stare at the gauge the moment you twist the key you will see it move.  The distance between the 1/4 marks is surprisingly close to 25 gallons.  If the needle moves by one "width" it is about a gallon.   You don't have to start the engine, just turn the key to "on" once a week and you'll know within a gallon or two how much fuel is being used by your HydroHot, our generator if using it.

At the Boot Scootin Stock Yards rally we chose to run the generator continuously so we could keep the windows closed, the dust out and the dog cool.  The needle "jumped" about 12 gallons when I turned the key. 

My best estimation is that turning the diesel on for showers and dishes only consumes about a cup a day as long as the electric is on continuously.

All of that said, I think your HydroHot is not working correctly.  For two or three of our ten years, our hot water performance was marginal.  We bought it new and knew what it should be like.   Standard household temperature is (I think) normally set to 125 degrees.  The HydroHot has a bunch of parts in it that should provide a steady 125 degrees for long enough wash the dishes and certainly your hands.  Turning the diesel on to get it hotter only means one or two parts out of the bunch aren't working well.

During our two or three years of crappy hot water performance, two HydroHot technicians, that I like and and respect failed to find the problem.  At the Bend Beer rally last summer Jerry Carr arranged for John Carrillo to provide service to several of us at a group rate.  John was busy for two days.

After describing our issue, John advised that it would take time to do proper trouble shooting.  We agreed to pay for the time it took.  He measured and tested everything.  He had one tool I'd never seen before.  After about an hour, maybe longer, John said that he had tested everything testable.  The last part on his procedure could appear to be functioning even if it was not working at full capacity.  It is called the "stir pump".   The only definitive way to find out was to put in a new one.

It might be interesting that the "new" one did not look like the old one or fit where it was installed.   I know ours was replaced once at about year 3.   Now twice.  I think I understand that AquaHot had to make a change due to high failure rates. 

As soon as John replaced the stir pump, we had hot water just like in a stick house, like it should be.  Although I didn't notice it much when the stir pump was not working, the diesel had to run longer for cabin heating as well. 

John left me with the old stir pump.  I remember when the first one broke, I took it apart and found the magnetic clutch drive inside was in pieces.  This time I hooked up the wires and some tubing and found it was pumping, but not much.  I think the magnet had weakened. 

The stir pump is not cheap.  Nothing for a HydroHot is cheap.  But, I'll bet a beer or a cup of coffee you need a new one.  We've had two fail and the replacement is a different design. 

Steven Hoffman

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #6 on: December 20, 2014, 08:55:35 PM »
I changed the pump on mine to a March 809 BR or 809 BR C (can't remember which one, it was what was in stock at the time as it was 10 deg out when it quit).  Been running fine since Jan 2009. 

Bill do you know what brand you have now?

Bill Sprague

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #7 on: December 20, 2014, 09:00:14 PM »
.....
Bill do you know what brand you have now?
I don't.  All I know is that it is the one that was on John Carillo's truck.  It's in the storage yard 15 minutes away or I would check. 

Teresa Owen

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #8 on: December 21, 2014, 02:27:48 AM »
Thank you to everyone that responded.  We have an appointment with Sun Bum RV here in Yuma, AZ after the first of the year....we will add the Hydro Hot to our list of things to checkout! 

This Beaver Monterey is our first motorhome and we have only had it 4 months, so we have a lot of questions!   Not at all like our 2008 Arctic Fox Travel Trailer!

Bill Sprague

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #9 on: December 21, 2014, 02:40:51 PM »
Thank you to everyone that responded.  We have an appointment with Sun Bum RV here in Yuma, AZ after the first of the year....we will add the Hydro Hot to our list of things to checkout! 

This Beaver Monterey is our first motorhome and we have only had it 4 months, so we have a lot of questions!   Not at all like our 2008 Arctic Fox Travel Trailer!
Teresa,

We traded a 24 foot Terry Lite "Northwest Edition" fifth wheel in on our 04 Beaver Monterey.  We've had it since 2003, driven it 120,000 miles and spent about 2500 nights in it.  It is my favorite home. 

Please put me on your speed dial and email address book so you can contact me any time there is a possibility that I can provide any insight into the mysteries of your Monterey.


Teresa Owen

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #10 on: December 21, 2014, 03:38:55 PM »
Thank you Bill Sprague!  Will keep you in mind for answers!  I noticed that you are located in Milton, WA.  We are from Richland, WA.

Bill Sprague

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Re: Diesel Consumption Using Hydrohot for Water Only
« Reply #11 on: December 21, 2014, 04:42:46 PM »
Thank you Bill Sprague!  Will keep you in mind for answers!  I noticed that you are located in Milton, WA.  We are from Richland, WA.
We went to college in Walla Walla back in the 60s.  We worked and lived in Yakima for several years.  We are hosting a rally in Toppenish this spring.  Please join us. 

Since you wrote you are relatively new to this club, please consider that the most fun we have is at rallies.  You get a formal invitation to every one of them in what we call the Beaver Tales that is published four times a year.