Antifreeze and Boiler antifreeze. These two are very different.
Boiler anti-freeze is intended for use in boiler systems and has a different chemical composition than antifreeze intended for RVs, automobiles and trucks. Camco has pink RV plumbing and RV freeze ban antifreeze in addition to their pink boiler antifreeze; be sure to use the boiler antifreeze in your Aqua-Hot system.
Starting with 2003 year model coaches, Foretravel started using Propylene Glycol based antifreeze, manufactured by Camco Manufacturing Inc. All Aqua-Hot systems manufactured after 2002 must use Propylene Glycol antifreeze. Aqua-Hot heating systems use boiler-designated antifreeze that is rated GRAS — Generally Regarded As Safe.
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. The color your system has depends on the model year of your motorhome.
TIP: Don’t mix colors in your Aqua-Hot system. Mixing pink and green boiler antifreeze produces a brown color that may be confused with corrosion, creating unnecessary service expense.