BAC Forum

General Boards => Technical Support => Topic started by: Fred Cook on October 12, 2017, 07:47:25 PM

Title: Where is my hot water??
Post by: Fred Cook on October 12, 2017, 07:47:25 PM
Just bought this Patriot Thunder and had the Hydro Hot system worked on to the tune of $1700.... very painful.  Heat is great but the hot water last only about a minute before it starts to go cold again.  Am I supposed to have a hot water reservoir somewhere like maybe 10 gallons?  Thanks
Title: Re: Where is my hot water??
Post by: David T. Richelderfer on October 12, 2017, 08:01:29 PM
Our AquaHot heats water by three ways 1) using its diesel burner, 2) using its electric element, and 3) using the engine's heated coolant when traveling.  If the diesel burner is operating, then you should have hot water until the fresh water tank runs dry.  Our electric element water heater will provide enough hot water for two showers of reasonable length.
Title: Re: Where is my hot water??
Post by: Joel Ashley on October 12, 2017, 09:17:41 PM
As long as the diesel burner has been turned on, you shouldn't run out of hot water.  In fact, to prevent hits of cool water in the shower, the system prioritize hot water, turning off floor heat exchangers and space heat in order to do so.  When the hot water demand ceases, space heating resumes.  Most owner's electric element won't keep up with a very hot shower's demand, so they kick on the diesel side beforehand. 

If your diesel burner is in fact working, you should be able to hear it and sense fumes from its exhaust outside.  If it is okay, then I'd next be suspicious of whoever worked on the unit's not setting or checking it's mixing valve properly.

You'll find AquaHot/HydroHot manuals for troubleshooting info on the Club's Coach Assist page.

Joel
Title: Re: Where is my hot water??
Post by: Steve Huber Co-Admin on October 12, 2017, 09:29:13 PM
Fred,
There is no water reservoir. The HH acts as a boiler and heats water on demand. If water starts hot and gets cold, does it then get warm/hot again? If so, the mixing valve may be acting up. It's purpose is to add cold water to the boiler output to get the temperature to a reasonable level. As Joel indicated you can find all the manuals on the Coach Link / Coach Assist page (Private Members Only board). Here is a good resource for the manuals.  http://www.aquahot.com/Library.aspx
Steve
Title: Re: Where is my hot water??
Post by: Fred Cook on October 13, 2017, 01:15:27 AM
Thanks all! Here is what they did.... replaced the mixing valve, replaced the stir pump, and replaced the circuit board that plus the initial diagnostic and labor cost a bunch. I talk to the repair shop today by phone and they indicated that maybe my water pump flow was too high. They said the system works on 1.5 gallons per minute and my pump is 3.5 gallons per minute. I find it hard to believe that the water flow would be too high for the system to produce continuous hot water. They also indicated they will Come to my house tomorrow (90 miles away) if we cannot solve it over the phone.
Title: Re: Where is my hot water??
Post by: Keith Moffett on October 13, 2017, 01:22:20 AM
Fred
I second Steves comment.  Get yoir model number off the outside of your HH and go to Aquahot.com/libraries and scroll through the owners manual and the parts manual.  This will familiarize you with how it works etc and ease your mind some.
The mixing valve is my guess.  If you are getting extra cold city water the HH works harder and perhaps the shop uou were at turned down the temp setting on the mix valve.  Our valve is set just above middle and may need to go up a bit.
Also, in the manuals there is a blow up diagram of your HH that helps you know where everything is and what it looks like!

Best
Keith
Title: Re: Where is my hot water??
Post by: Keith Moffett on October 13, 2017, 01:27:45 AM
Sounds like good intentions at that shop but......
We have not had the HH but have had the old Hurricane (even older) and a 3.5 GPM pump with no problems as described.  If they replaced the mixer valve did they turn it way down?
Title: Re: Where is my hot water??
Post by: Fred Cook on October 13, 2017, 02:14:48 AM
Sounds like good intentions at that shop but......
We have not had the HH but have had the old Hurricane (even older) and a 3.5 GPM pump with no problems as described.  If they replaced the mixer valve did they turn it way down?

Actually, they set it to 135 degrees. Hope this gets settled soon. Not paying them another penny. Thanks!
Title: Re: Where is my hot water??
Post by: Bill Sprague on October 13, 2017, 02:15:57 AM
My guess is that it is not the mixing valve.  Even if stuck, it would be consistently and continuously the same.  Maybe too hot, maybe only warm, but consistent. 

My other guess would have been the stir pump, but you have a new one.  But, even a new one could be defective.  I bought three in 12 years!

My last guess is that it is not staying lit.  If you are running hot water, the burner should be running constantly.  Is it running?

The HydroHot is a wonderful system when working.  But, there are so many interdependent parts, that only a very few technicians could figure it out if it was malfunctioning.  It is too complex for normal people to understand and there are many models. 

The last time (of several) that ours broke, the technician looked at me and said, "A complete trouble shooting will take me a couple hours.  Are you willing to pay me for that?"   I did.  Among other things, the ratio of coolant to water was way off the target after years of use.  The burner tube was cracked.  And the stir pump worked, but only at about 50%.  When he was done, the shower returned to being a wonderful experience.

Get a good technician!
Title: Re: Where is my hot water??
Post by: Bryan Beamon on October 13, 2017, 03:46:26 AM
Fred, another thought ,what does your anti-freeze look like. Is it pink or brown? If it is not pink you should change your anti-freeze at least every 10 years to maintain the heat transferability. Just another possibility.
Title: Re: Where is my hot water??
Post by: Steve Huber Co-Admin on October 13, 2017, 05:04:49 AM
Bill,
Mixing valves can be intermittent. I had one that would alternate between hot (normal) and cold randomly even in the time it took for a shower. Changed it out and problem disappeared.
Steve
Title: Re: Where is my hot water??
Post by: Bill Sprague on October 13, 2017, 01:23:35 PM
Steve,

At about year 2, the HydroHot would not produce consistent hot water.  The mixing valve was changed out.  We still had inconsistent hot water.   Two "expert" efforts later, the stir pump was changed out and the hot water became consistent, like new.  That stir pump broke around year 7 and we got another one. 

The point that I'm trying to make is that there are so many moving parts in the Hydro/AquaHot systems that even the best RV techs can be flummoxed in figuring them out when they are not working.   It is only my experience, but success at the many repairs of ours did not come until we started picking techs carefully.   In our decade of ownership, the HydroHot was the most expensive component in the entire Monterey. 

FWIW, the mixing valve is not a HydroHot made part.  It is a common part made by a major company (Honeywell??).  I think even Home Depot has them.  One of ours came with a tag that said it had required maintenance.  Once a year you have to rotate the knob to the stops and put it back where you had it.  If it won't do that, it is broken!

Steve, could you move the knob on the sticky one that you replaced?

Bill

Title: Re: Where is my hot water??
Post by: Bill Sprague on October 13, 2017, 01:37:18 PM
Fred, another thought ,what does your anti-freeze look like. Is it pink or brown? If it is not pink you should change your anti-freeze at least every 10 years to maintain the heat transferability. Just another possibility.
Bryan,

We had the same Monterey for 12 years.  They normally take a little fluid once or twice a year.  Towards the end of our ownership we had to have the "complete trouble shooting".  The first thing John Carillow (http://heatmyrv.com/) did was measure the mix with some sort of eye glass.  (A spectrometer??).   He explained that the normal loss of fluid each year is from water evaporation.  The coolant does not evaporate.  So as I added the 50/50 mix I was increasing the concentration.  He had to take out quite a bit of fluid and replace it with distilled water to get the optimum mix.  He suggested that in the future we add only distilled water.   Of course if you are adding because of a leak, that would be different. 

I asked if I should completely replace the fluid after 12 years.  Even though ours looked pretty dirty, he said no. 

It can be pink or green.   A lot of HydroHots used green.  A lot of AquaHots used pink.  Ours used green.  I don't know if adding pink to a green system, or the other way, is OK or not. 
Title: Re: Where is my hot water??
Post by: George Harwell on October 13, 2017, 04:08:18 PM
Fred, don't know if this has anything to do with your problem but make sure the outside shower faucets are turned off. I also have heard over the years about the stir pump not mixing the incoming cold water. It sure is suspect to me. Good luck.
Title: Re: Where is my hot water??
Post by: Steve Huber Co-Admin on October 13, 2017, 05:19:38 PM
This article covers a number of issues with the HH/AH.  http://beaveramb.org/listings/location/aqua-hot-hydro-hot-heating-systems/
Bill, the device you were referring to is a refractometer https://www.amazon.com/Goodes-Refractometer-Handheld-Scale-Specific-1-000-1-130/dp/B0716HRSL7/ref=sr_1_12?ie=UTF8&qid=1507911489&sr=8-12&keywords=refractometer and should be used to determine proper mixture for boiler (red) antifreeze. My faulty mixing valve was a Honeywell. The control would turn but was very stiff if I remember correctly
Steve
Title: Re: Where is my hot water??
Post by: Fred Cook on October 13, 2017, 06:03:30 PM
Ok.... now I am getting sustained hot water... over 10 minutes hot water in the shower.  The only thing I did was move it out of or RV shelter and into the driveway so I could hook up to water and trouble shoot again with the repair people on the phone.  It started up and operated normally.  Here is my theory.... while parked under the shelter the hydro hot exhaust pile was only about 10 inches away from the shelter wall.  This produced higher temps in that area that may have shut the system down.  Does that make sense?
Title: Re: Where is my hot water??
Post by: Gerald Farris on October 13, 2017, 06:36:13 PM
Fred,
Your theory about the exhaust being 10 inches from the wall causing your problem does not sound reasonable.

Gerald
Title: Re: Where is my hot water??
Post by: Fred Cook on October 13, 2017, 11:00:46 PM
Fred,
Your theory about the exhaust being 10 inches from the wall causing your problem does not sound reasonable.

Gerald

  Yeah, you might be right. It’s just that it is odd how it started working when I moved the motorhome into my driveway in the open air. I just hope it stays working good. Thank you for your response.
Title: Re: Where is my hot water??
Post by: Keith Moffett on October 14, 2017, 05:28:29 AM
Hi Fred
Silly things happen sometimes.  Sounds like moving your coach was the equivelant of a swift kick.  Perhaps something was sticking and the movement popped it loose.  That in mind then the first thing I would do is look at the high and low limit switches.
The HH will be a bit different but in the AH there are one each for running on shore power and one each for 12 volt.  When you moved were you still on shore power or did you unplug?