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Aqua Hot Maintenance Question - coolant condition

Yahoo Message Number: 89809
My first coach with Aqua Hot. I am doing proactive maintenance, replaced fuel filter and burner nozzle. All the boiler coolant I see is pink but the coolant I can see in the overflow bottle is very dark...dark green, blackish green.
So, should I drain, flush and refill with new boiler coolant? What do you folks with more Aqua Hot experience say?

Gary

'07 Allure 470 #31578

Re: Aqua Hot Maintenance Question - coolant condition

Reply #1 –
Yahoo Message Number: 89810
This is from Roger Berke, they Aqua Hot "guru" http://www.rvhydronicheaterrepair.com/
You can confirm this with him or with Aqua Hot technicial support at http://www.aquahot.com/
The coolant in your Aqua-Hot does not need to be routinely changed. The system is a 'closed' system and does not pick up engine contaminates.
The Camco coolant will change color to look like Coke-Cola. This is normal and does not seem to hurt anything.
The PH of the coolant should be checked periodically. The pH of the Boiler antifreeze should remain between 7.5 and 9.3; if it tests lower than 7.5, galvanic corrosion may be accelerated.
The only reason to change coolant is PH out of normal range or something added to coolant that should not be there.
If your Aqua-Hot (model AHE-100-03, AHE-100-04, HHE-x00-08 or HHE-x00-09) still has any PEX parts they should be changed to brass. The plastic parts are very prone to failure.
- Roger Berke -

Lonny & Diane Livingston
'04 Allure #31065

Re: Aqua Hot Maintenance Question - coolant condition

Reply #2 –
Yahoo Message Number: 89814
Gary - As many know here, I think the HydroHot is an expensive maintenance nightmare owing to numerous poor design problems. So that's all the more reason(s) to be proactive with maintenance. The unit is also difficult to service IMHO. Below is a partial list of projects I've undertaken to keep the HydroHot working properly. Some suggest improvements. As of late the unit is working quite well now since I took a couple of pounds of calcium out of the heat exchanger (through no fault of the HydroHot). In addition to what's below I had issues with the Webasto turbine motor not reliably shutting off after its purge cycle. It would go on, off, on, off, on, off, etc. before finally shutting off. This was fixed with a new control box. Check the price on these for some sticker shock! The box failed about 3 years into the burn which I think is well short of where it should have failed given the price. The HydroHot is an expensive option at about $8k. And they installed cheap plastic drain plumbing which should be replaced at an additional cost to you. I did this using brass fittings and a good quality valve to include a hose barb for easy draining of the unit.
HydroHot also used a cheap plastic level switch ($13) too which fails quickly. The more expensive brass body switch ($80) uses a cheap plastic float which breaks off. I think the really good switches are about $250. I've replaced mine three times now. As for the magnet and plastic float that break off, we're not really sure where they go and if this will clog a recirculating pump inlet or not. It's next to impossible to remove these parts from the tank.
http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=204#Post204 - Removing calcium

http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=142#Post142 - Level tank sensor project

http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=141#Post141 - Cost of HydroHot

http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=108#Post108 - Stir Pump

http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=107#Post107 - Low tank level switch

http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=95#Post95 - Anti-Scald valve

http://www.muniac.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=86#Post86 - Webasto turbine motor

I've dumped a little over $2k so far in parts. And I do all the work myself so add that much in again for labor if you are relying on someone else to do the work.

The Camco Boiler 100, fuel filter and nozzle are the least of the problems. Nozzles get their orifice enlarged over time. This causes the burner to run rich. Replacement is suggested annually. Probably not a bad idea. Propylene-glycol can become acidic over time. A Ph test is the only way to check on this. Replacing the fluid will, of course, restore proper Ph and heat transfer properties. If there are alkaline additives, I'm not familiar with them. I always mix the Camco concentrate with distilled water. The idea is to avoid mineral contamination. Make sure to use steam distilled water, not the cheap filtered stuff. Last I checked steam distilled was about $1.25/gal.
Shouldn't break anyone's budget. Good luck.

Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html

Re: Aqua Hot Maintenance Question - coolant condition

Reply #3 –
Yahoo Message Number: 89815
Scott said " . . . couple of pounds of calcium out of the heat exchanger . . ."


I'm so glad I've been using a water softener on all my fresh water, now going back 5 years.


Lee

Lee (leozbrowski@...) 2007 Country Coach Intrigue 12153
CAT C-13

Re: Aqua Hot Maintenance Question - coolant condition

Reply #4 –
Yahoo Message Number: 89816
While we're at, Scott doesn't have a couple of pounds of calcium, rather a couple of pounds of calcium salts.


Lee

Lee (leozbrowski@...) 2007 Country Coach Intrigue 12153
CAT C-13

Re: Aqua Hot Maintenance Question - coolant condition

Reply #5 –
Yahoo Message Number: 89817
You also need to maintain a 50/50 water to boiler fluid mix in order to have proper heat transfer.

Dan 2006 Allure 31348 C-9

Re: Aqua Hot Maintenance Question - coolant condition

Reply #6 –
Yahoo Message Number: 89818
Gary

Cleaning the combustion chamber is part of the service and inspection for cracks in the combustion chamber tube. I have also replaced the plastic float which will break when it is not convenient. There is a fluid level sensor which has no moving parts.

Dan 2006 Allure 31348 C-9

Re: Aqua Hot Maintenance Question - coolant condition

Reply #7 –
Yahoo Message Number: 89819
Lee - We too have been using a water softener for the very purposes of reducing and/or avoiding calcium. I can't explain this buildup. Unless the softener isn't removing as much calcium as expected. We have test strips but don't use them. Maybe it's time for a rethink on monitoring. I guess the calcium salts are a better condition. They dissolve in vinegar.

Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html

Re: Aqua Hot Maintenance Question - coolant condition

Reply #8 –
Yahoo Message Number: 89820
Camco calls for mixing one part propylene glycol (concentrate) with 2 parts of water. This isn't a 50:50 mix ratio.

Best - Scott

2006 Allure 430 40' #31349

(Bus-Stead Lemon) My Allure Page http://www.muniac.com/Allure%20Page.html

Re: Aqua Hot Maintenance Question - coolant condition

Reply #9 –
Yahoo Message Number: 89821
Could be marginal softener effectiveness. And you fulltime so lots or water going through the system. Hard to explain.


Lee

Lee (leozbrowski@...) 2007 Country Coach Intrigue 12153
CAT C-13

Re: Aqua Hot Maintenance Question - coolant condition

Reply #10 –
Yahoo Message Number: 89822
OK folks, I appreciate all the suggestions. I did check the website suggested and while that fellow says it is normal for the coolant to darken over time and just ensure that the pH is acceptable, I am not sure I want to leave that coolant in there. So, I called Aqua Hot and their tech guy, while acknowledging that the coolant will darken over time, he also suggested I don't know how the thing has been serviced, who put what in it, and if they used the wrong coolant or tap water to dilute it, I could have problems. He also acknowledged the boiler coolant is not cheap and I need to be prepared to have about 8 - 9 gallons of the mix. He also said Camco made the pH test strips. I inquired if I could use the coolant pH test strips (Cool Track??) but he only said use the Camco strips.
At this point considering the potential cost of issues with this new-to-me gizmo, I am thinking I will drain, flush and refill just to be sure. While I am at it, I will do the white vinegar flush.

Gary

'07 Allure 470 #31578

Re: Aqua Hot Maintenance Question - coolant condition

Reply #11 –
Yahoo Message Number: 89827
Gary

Assuming you are not as old as I am buy a refractor from Roger it will come in handy for testing your coolant. Also, do some research on coolant I have seen it as cheap as $15 to $25 a gallon and you can also find deals on buying it by case which I believe was 4 gallons in a box. My coolant had gotten extremely dark and there was a significant improvement after I flushed flushed the system.

Dan 2006 Allure 31348 C-9

Re: Aqua Hot Maintenance Question - coolant condition

Reply #12 –
Yahoo Message Number: 89828
I am talking about the normal boiler fluid which comes in 1 gal containers not the concentrate which was developed to reduce shipping costs.

Dan 2006 Allure 31348 C-9