Aqua Hot losing coolant

[jonohio]

Hi folks,

My 430 aquahot is losing coolant somehow. I keep having to add fluid to the expansion tank.

I have also noticed a coolant leak near the engine, i have some small puddles on the driveway - it looks like one of the larger pipes on the upper driver side.

My question - could the two be related? Does the engine and aqua-hot share coolant? I thought not as both have their own coolant expansion tank.

[gemert]

Originally Posted by jonohio

Hi folks,

My 430 aquahot is losing coolant somehow. I keep having to add fluid to the expansion tank.

I have also noticed a coolant leak near the engine, i have some small puddles on the driveway - it looks like one of the larger pipes on the upper driver side.

My question - could the two be related? Does the engine and aqua-hot share coolant? I thought not as both have their own coolant expansion tank.

Possibly. On my MH the coolant from the HH goes to the engine and is heated while the engine is running. Also you have heat registers in the back and one of the coolant lines going to supply the rear register may be leaking.

[jonohio]

Thanks Jerry. Good point. We have looked all over and it doesn't appear like any of the AH registers are leaking.

Originally Posted by gemert

Possibly. On my MH the coolant from the HH goes to the engine and is heated while the engine is running. Also you have heat registers in the back and one of the coolant lines going to supply the rear register may be leaking.

[Topman]

I have the exact same coach.
The coolant does circulate from the Aqua Hot to the engine. Engine heat provides hot water for the AH to function without the burner operating.
Hopefully you can repair the hose/leak at the engine.
Iver.

[jonohio]

Thx for the reply Topman, nice coach!

Yes, I understand how the AH works, but i wasn't sure if the lines into the engine are closed and just pass through the engine - or if they share the same coolant.

At least it's not a major leak, yet.

Originally Posted by Topman

I have the exact same coach.
The coolant does circulate from the Aqua Hot to the engine. Engine heat provides hot water for the AH to function without the burner operating.
Hopefully you can repair the hose/leak at the engine.
Iver.

[Spk64]

Originally Posted by jonohio

Thx for the reply Topman, nice coach!

Yes, I understand how the AH works, but i wasn't sure if the lines into the engine are closed and just pass through the engine - or if they share the same coolant.

At least it's not a major leak, yet.

Unless they changed something they are both closed systems. There is a heat exhanger in the Aquahot tank that the engine coolant circulates through.

[gemert]

Originally Posted by jonohio

Thx for the reply Topman, nice coach!

Yes, I understand how the AH works, but i wasn't sure if the lines into the engine are closed and just pass through the engine - or if they share the same coolant.

At least it's not a major leak, yet.

If like mine they do not share coolant. I do not believe any of them do. Some newer have different type of coolant in the AH than the engine has so no.

[jonohio]

Hmmm.

Anyone know if the it's possible for the aquahot burner to eat coolant internally? I opened up the service panels on the AH and there are no signs of a leak.

I wonder if it's like a car with a bad head gasket - where the coolant can leak/burn in the combustion process yet not have any visable leaks.

Originally Posted by gemert

If like mine they do not share coolant. I do not believe any of them do. Some newer have different type of coolant in the AH than the engine has so no.

[Spk64]

Originally Posted by jonohio

Hmmm.

Anyone know if the it's possible for the aquahot burner to eat coolant internally? I opened up the service panels on the AH and there are no signs of a leak.

I wonder if it's like a car with a bad head gasket - where the coolant can leak/burn in the combustion process yet not have any visable leaks.

If there is a leak in the burner yes. I believe this will show up in the burner chamber as a white residue and may notice some difference in the exhaust.

[DrDaveMA]

So a couple of different questions.
1) the coolant in your AH is non toxic, based upon the premise that if some of it leaked into the hot water tank/line it would not kill you. If you were to consume something me of your engine coolant it may not kill you, but it will make you wish you were dead!
2) can the AH eat coolant, yes if there is a leak into the hot water lines, although it normally is the other way around, your water is normally at 60 PSI (many CG's have considerably lower pressure) so it would shoot out the "radiator cap" on the AH.
3) engine antifreeze is circulated from the engine through the AH, the hot water loop is separate. You can use the AH to preheat your engine or use your engine to keep you AH hot while driving. I do this all the time, just set your thermostat to 68 and drive away, as soon as your engine comes up to temp the AH will give you heat throughout the coach.

[tophog]

While I have a different unit (600D) when we first bought our 2007 Dynasty used last year the AH coolant bottle was nearly empty.

I ordered a gallon and topped it off and called it good only to find a few days later it was nearly empty again. We were running the AH nearly 24x7 as it was middle of winter/snowing in Oregon. I ordered another gallon and topped off again ...and over the course of a week it continued to go down so I kept filling.

Eventually it settled out and has retained the correct level ever since. I too looked for leaks everywhere and finally chalked it up to having air in the system or something along those lines.

When we left Oregon to AZ in late Jan. I had the system serviced at Cummins Northwest and they found nothing wrong and just did the typical annual maintenance.

[relaxn]

Originally Posted by jonohio

Hi folks,

My 430 aquahot is losing coolant somehow. I keep having to add fluid to the expansion tank.

I have also noticed a coolant leak near the engine, i have some small puddles on the driveway - it looks like one of the larger pipes on the upper driver side.

My question - could the two be related? Does the engine and aqua-hot share coolant? I thought not as both have their own coolant expansion tank.

Depends what you are asking about. There are two types of fluid and they are both related, sort of....the fuel for the diesel burner(Usually pink) in the Aquahot system and the coolant for your RV(usually green). I have the 450D and the actual engine coolant(green) IS part of the Aquahot system but different from the diesel burner fluid(Pink, in the AH system). The engine coolant(green) is also used as the "preheat" liquid that is a feature of the Aquahot system. There is a circulation pump at the Aquahot system that runs from the Aquahot system at the front of the coach(in mine) to the engine. You fire up the "Engine preheat" and that gets the Aquahot system going that circulates the warmed up coolant(green) through the engine to preheat it.

I know this because the the $50 circulation pump(not in use at the time, the pump just cracked and started spitting out engine coolant) on our coach sprung a leak and drained our engine coolant and left us overheated on the side of I-10. :-( I never imagined the two were connected until then. It was a shock to see my "Overheat" light come on and see engine coolant leaking out near the front of the coach.

[gemert]

Originally Posted by jonohio

Hmmm.

Anyone know if the it's possible for the aquahot burner to eat coolant internally? I opened up the service panels on the AH and there are no signs of a leak.

I wonder if it's like a car with a bad head gasket - where the coolant can leak/burn in the combustion process yet not have any visable leaks.

Yes it can happen. Not an expert but you will probably be able to see it as white smoke or steam in the exhaust. Again not an expert. Try the manuals on Aqua Hot's website.

[Jeff753]

Bad radiator cap?


Jeff
2001 Dynasty Regent tag axle
Cummins 350 8.3 ISC
2012 Jeep Grand Cherokee Overland
FMCA ENERGIZED Task Force Chairman