60,000 BTU/h

Use the Propylene Glycol-Based Antifreeze Protection chart to determine the protection you require in your Aqua-Hot system. Freezing Points are temperatures at which ice crystals form. Even below those temperatures, a slushy condition exists which may flow. Burst point is the temperature where damage will occur to the coach; at antifreeze solution percentages above 35%, burst protection is below -50 degrees F.

The propylene glycol antifreeze level of the solution in the Aqua-Hot heating system needs to fall between 35% and 50%. The Freeze Point is the temperature at which ice crystals will start to form in the antifreeze solution. Burst Point is the temperature where damage will occur to the coach.  DO NOT exceed 50% Propylene Glycol in an Aqua-Hot System.

Inspect your Aqua-Hot system monthly. Run your Aqua-Hot system to operating temperature. When it is warm and the coach is level, visually check the Aqua-Hot expansion bottle to see if the antifreeze level is at the HOT mark. This gives you a true indication of the antifreeze solution level.

When you need to add antifreeze, determine the freeze protection you need in the final antifreeze solution and mix your replenishment solution accordingly. This will require a refractometer for accuracy.

Where do I buy boiler antifreeze for your aqua-hot system?

Camco pink boiler antifreeze is available directly from Aqua-Hot as well as our site. Century green is available directly from Aqua-Hota as well.

*except for Aqua Hot 125D and 125G systems. *125D and 125G systems use a mixture of 50/50 Ethylene Glycol antifreeze and distilled water. Which is available at most big box or automotive retailers.

After you obtain boiler antifreeze with the same color as your current system, it is critical that you determine the antifreeze mixture of the Propylene Glycol boiler antifreeze in your system. Water will evaporate from the boiler antifreeze mixture over time, concentrating antifreeze mixture and changing the ratio in the system. 

Use a calibrated coolant/antifreeze refractometer and measure the ratio of Propylene Glycol in your antifreeze solution.

Caution: Automotive “ball type” hydrometers that measure ethylene glycol in the engine’s coolant system will not properly measure propylene glycol.

The correct antifreeze solution mixture for protecting your Aqua-Hot system depends on where you are and how cold it is — or can be. 

Use the Propylene Glycol-Based Antifreeze Protection chart to determine the protection you require in your Aqua-Hot system. Freezing Points are temperatures at which ice crystals form. Even below those temperatures, a slushy condition exist which may flow. Burst point is the temperature where damage will occur to the coach; at antifreeze solution percentages above 35%, burst protection is below -50 degrees F.

Aqua-Hot recommends the antifreeze solution contain between 35% and 50% propylene glycol boiler antifreeze to water mixture. Too much antifreeze lowers the heat transfer capability, causes sticking check valves in the heating zone lines, and may coat the system’s interior surfaces resulting in lower water and interior cabin temperature levels. DO NOT exceed 50% propylene glycol in an Aqua-Hot system. 

Your Aqua-Hot Factory Authorized Service Center will assure the proper ratios. If you do it yourself, check the color.

The green color Century brand boiler antifreeze is pre-mixed at approximately 37% propylene glycol and requires NO dilution and it is not necessary to mix Century boiler antifreeze with water before adding it to the Aqua-Hot system’s antifreeze solution.

The pink color Camco boiler antifreeze comes two ways: There’s a pre-mixed gallon and a concentrated quart.

The pink color Camco boiler antifreeze comes two ways: There’s a pre-mixed gallon and a concentrated quart.

The Camco pre-mixed gallon has approximately 67% propylene glycol. DILUTION IS REQUIRED to achieve the proper antifreeze to water ratio. Add one (1) gallon of Antifreeze to one (1) gallon of deionized or distilled water to reach a 35%-38% Propylene Glycol Level. Check the diluted level of Propylene Glycol with a refractometer before adding the new solution to the Aqua-Hot system antifreeze solution.

The Camco 32oz. concentrate contains approximately 97% propylene glycol. DILUTION IS REQUIRED. Add one (1) quart of Antifreeze to two (2) quarts deionized or distilled water to reach a 35%-38% Propylene Glycol Level. Check the diluted level of Propylene Glycol with a refractometer before adding the new antfreeze solution to the Aqua-Hot system.

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. Camco and Century may not honor the warranty of their product if mixed with another company’s product.

Camco and Century may not honor the warranty of their product if mixed with another company’s product. 

Motorhome manufacturers generally fill the Aqua-Hot with Century brand (green in color) or Camco brand (pink in color) boiler antifreeze.  Mixing these two colors together may cause discoloration of the antifreeze solution in your Aqua-Hot.

When your visual inspection level indicates a need to replenish the antifreeze solution:

1. Use the same color boiler antifreeze that’s in your heating system.
2. Determine the Propylene Glycol antifreeze protection level you want, using the chart below.
3. Make sure you have the antifreeze amount you need to fill your system to the HOT mark on the expansion tank. See back for details on mixture for your color of antifreeze.
4. Bring your heating system to operating temperature. This prevents the overflow that will happen when coolant is added to a cold tank.
5. Remove the expansion tank cap. TIP: Solution in the system is very, very hot.

Wear eye and skin coverings to protect against splashes or spray.

6. When refilling, open the Air Release Valve located on the expansion tank connection on the Aqua-Hot system to release air pockets; close the release valve when antifreeze appears at the Air Release Valve. Fill until you reach the HOT mark on the expansion tank.