Aqua-Hot

[sg47619]

Has anyone changed the antifreeze in a 2001 Monaco Dynasty Aqua-Hot. 

[Bill C]

I have

[DavidL]

I have in a 2002 HydroHot...should be very similar.

So, other than a survey...did you have a question?

 

[sg47619]

I guess I didn’t say it the way I should have, should I change the car antifreeze in it to boiler fluid. 

[DavidL]

"

Propylene Glycol Boiler Antifreeze In 2002, Aqua-Hot changed the system design and in 2003 systems started using Propylene Glycol-based boiler antifreeze rated Generally Regarded AS Safe (GRAS).

All Aqua-Hot Systems manufactured after 2002 must use Propylene Glycol antifreeze, including Hydro-Hot™, Aqua-Hot 250P™, Aqua-Hot 250D™, Aqua-Hot 375D™, Aqua-Hot 375LP™, Aqua-Hot 400D™, Aqua-Hot 400P™, Aqua-Hot 450D™, Aqua-Hot 525D™, Aqua-Hot 600D™, and Aqua-Hot 675D™. DO NOT use Ethylene Glycol or Propylene Glycol automotive antifreeze in these Aqua-Hot systems.

Ethylene Glycol Antifreeze Ethylene glycol antifreeze is toxic, does not have the GRAS label and is not suitable for an Aqua-Hot system manufactured after 2002. Ethylene glycol was used in pre-2002 Aqua-Hot systems with the exterior domestic hot water loop design. Ethylene glycol can be used in these pre-2002 systems, as well as GRAS-labeled propylene glycol boiler antifreeze."

 

[Dr4Film]

It depends on the model of Aqua-Hot that is installed in your coach. The difference is whether the fresh-water loop is located outside or inside the boiler.

Roger Berke published a document listing which models can use the old green Ethylene Glycol and which models must use the Propylene Glycol antifreeze. You have to be a member of his forum in order to view the document linked below. If you are NOT a member, then I HIGHLY suggest that you become one especially if you own an Aqua-Hot or Hydro-Hot.

RV Hydronic Heater Repair - Hydronic Heater Model List

I have also attached a document written by Roger Berke about types of coolant.

Types of Aqua-Hot Coolant.docx

[dandick66]

Before you tackle this job, you may want to get the antifreeze/fluid.  Good luck finding it at a decent price.  It looks like the Camco brand is no longer available, and the shipping on other brands is very expensive. 

[sg47619]

Thanks everyone, my model number is 100-00S. According the article from Roger Berke my is designed to use the old antifreeze type. 

[Bill C]

When I replaced my anti-freeze fluid, I worked with a trained Aqua Hot Tech and we used a pump to put the anti-freeze in, and to take it out, to reduce the risk of putting air in the system. 

Something you might consider doing.

We tied in to the drain valve to enter/exit the unit with the anti-freeze.

Bill.

[96 EVO]

6 hours ago, sg47619 said:

Thanks everyone, my model number is 100-00S. According the article from Roger Berke my is designed to use the old antifreeze type. 

I would keep using it then. Much cheaper than non-toxic boiler antifreeze, and should work just as well.

It's actually the distilled water that does most of the heat transfer. The antifreeze is just to eliminate freeze damage and provide some corrosion protection.

Edited April 9, 2022 by 96 EVO