Community Forums

JohnParker · 12-09-2011, 11:47 AM

Yesterday, while on the highway South of Dallas, the Engine Overheat Alarm came on. I coasted into a gas station parking area and found that the coolant hose on the lower driver's side of the engine had split. Eventually, after much crawling around under the engine and taking the floor out to access the top of the engine to trace the line, it became apparent that the line went to somewhere in the front of the RV and that there was a return line with associated valve just in front of and slightly above the split line. I closed the valves and refilled the reservoir with coolant, started the engine, checked for leaks and when all was well, proceeded on my journey.

The question is; are these lines part of the Hydro-Hot system? In the interest of not causing any more damage I did not operate the HH system until I spliced in some new sections of coolant lines. With the valves on the engine block closed; if these lines are part of the HH I would have been operating the burner with no flow, if these lines are not part of HH and only provide heat to the dash area I could operate the HH with the engine off and the valves on the block closed. If these lines are only for dash heat I could leave them closed and depend on HH for coach warmth. If they are part of the HH I fear that I am going to need to trace and replace the entire run of coolant hose.

Ronnie Bledsoe 2006 Dutchstar 43' · 12-09-2011, 02:05 PM

Newmar in 2006/2007 received and used some Hose for Hydro/Aqua Hot that was defective and would split ( this hose is black about 1" O/D and 3/4" I/)D. I had this happen to me. You might check with them and ask if they would pay for replacement as a known latent defect. There are several writeups on this subject on this forum. The dash heater hose is not the same hose and as far as I know is installed by Spartan whereas the Hydro/Aqua Hot hose is installed by Newmar.

Dave78Chief · 12-09-2011, 02:49 PM

Either the hoses going to the engine are part of the HH engine pre-option

or

They could be part of a Hot Water heater engine heat feature (allows you to have hot water at destination arrival). However, this would not be needed if the HH system is used to supply hot water to faucets.

Dave

JohnParker · 12-09-2011, 02:57 PM

The hose that split is the one on the driver's side of the engine. There is a valve about 18" inches below the top and 12" behind the front of the engine and another valve on the same side about 6" below the top and 3" behind the front of the engine. There is a black 1" OD by 3/4" ID hose attached to the valves. Is this the AquaHot system hose to which you refer?

harleyman134 · 12-09-2011, 03:39 PM

The HH heating solution is totally independant of the engine's cooling, and each requires different coolants/solutions. If your engine was overheating due to a split in a hose I don't think it would effect the HH system. The HH uses the heat from the engine coolant to heat it's solution to provide "free" heat while traveling down the road and I always assumed an enclosed line runs from the engine thru the HH solution and as the heated solution in this line pass thru the HH solution, heat is transfered from this line and heats the solution in the HH. But what do I know, I'll definately be following this thread to see how far off my theory is.

JohnParker · 12-09-2011, 04:48 PM

HarleyMan;

If your theory is correct, and I would like to think it is but need confirmation, then the coolant solution circulating from the engine through the hose that split is in a loop that exchanges heat with the solution in the HH system and the two solutions do not mix. If that is true, I should be able to close the two valves but still operate the HH. All that I give up is the on-the-road heat from the engine (MotorAide according to the handbook?) and the HH will have to operate on diesel 100% of the time.

I have sent queries to newMar and Aqua-Hot. We'll see what they say.

harleyman134 · 12-09-2011, 06:10 PM

John, there is a good hh group in "yahoo groups" that can provide you the info you are looking for. The name of the group is hydronicRVHeating.

Ronnie Bledsoe 2006 Dutchstar 43' · 12-09-2011, 06:14 PM

I don't know how this system works coolant wise but when my hose burst I lost engine coolant, engine temp went from normal to 235* before I could safely get off the road. There was NO loss of Aqua Hot boiler solution. I could not immediately get the hose replaced so folks at the Cummins place in Coburg Oregon turned 1 0f those valves off so that the engine coolant did not flow to the Aqua Hot system while I continued my trip and returned at a later date. Because of the coolant loss and use of water to get me going from the side of the road I had to have the engine flushed and new coolant in the cooling system before I continued my trip. Upon return to Coburg the hose was replaced from engine to Aqua Hot and valve turned back on.

JohnParker · 12-09-2011, 07:05 PM

Ronnie;

Your experience is very similar to mine... Traveling down the road all very normal. within just a few minutes the temp indicator went from a normal ~180 degrees to 240+. I was able to coast to a stop within a mile or two at an Exxon station as previously described.

I have confirmed that there has been no loss of fluid from the HH system. It is not likely that I will hear from NewMar or AquaHot before Monday. So, unless I hear otherwise, I will close both valves to stop circulation in the suspect lines and continue to operate the HH to keep from freezing in the coach.

Raca-roni · 12-09-2011, 07:30 PM

The Hydro Hot/ Aqua Hot have their own sealed cooling system. Nothing to do with the engine coolant. Those hoses are most likely the ones from the engine into the Hydro Hot for domestic hot water while the coach is being driven.

Ronnie Bledsoe 2006 Dutchstar 43' · 12-09-2011, 07:35 PM

John I downloaded the full Aqua Hot manual several years ago. It is in the M/H and when I go to storage area tomorrow I'll review it for any details on engine coneections.

Dave78Chief · 12-09-2011, 08:17 PM

Hydo-Hot and Aqua-Hot manuals are available here: Aqua-Hot Heating Systems Inc.

You will need to know the model you have.
Note: those are the achieved manuals for older versions. Use the back button at the bottom of the page for current models.

Here is the AquaHot/Hydrohot users forum: http://www.forum.rvhyd.com/
I believe IVR2 User Roger Berke is the POC for these systems.

Dave

dd950 · 12-10-2011, 09:00 AM

JohnParker

My 2001 Kountry Aire's Hydro Hot uses the engine coolant to provide
heat to the HH's coolant tank. (HH calls this Motoraide). The coolant leaves the engine (ISC Cummins) where you described via 3/4 in ID hoses. The hoses have Y's so the coolant can go to the HH and the dash heater.
I confirmed this with Newmar last week. Roger Berke at
Forums assured me the HH will function fine with the Motoraide hoses disconnected.

You are fortunate to have the shut off valves, my Spartan manual states I should have 2 valves, however...

I plan to repair my temporary fix this weekend.

JMichael
2001 Kountry Aire 4084

JohnParker · 12-11-2011, 08:49 AM

So far, so good;

I confirmed that the circulating line from the engine exchanges heat in the HH boiler but does not affect the HH otherwise. Closing the valves on the engine will only disable the dash heat and require the HH diesel burner to operate while driving for coach heat.

I expect to hear from NewMar on Monday but don't know what to expect... Roger is recommending some high quality replacement hoses that cost $175 per 50 ft roll. I'm sure it will take two to go all the way to the dash heater and back. I will probably do that because I really don't want to have to do it again in the future. It looks like an all-day job to pull the old hoses out and put in the new ones. I'm hoping NewMar will contribute the labor at least.

I will let everyone know how it comes out.