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Topic: Which Antifreeze for Aqua Hot 431/12 (Read 1654 times) previous topic - next topic

Which Antifreeze for Aqua Hot 431/12

I've search all over and I'm still not sure which antifreeze to use to top off my Aqua Hot antifreeze expansion tank. I have a Model 431/12, with serial #99978.

There's a sticker on the plastic tank that says to use a Texaco brand antifreeze.  That doesn't exist anymore.  George left me some 50/50 antifreeze (see attached pic) but told me that it was for the engine, not the AH.

I'm guessing just straight undiluted ethylene glycol antifreeze for a regular car engine that one can get at any Autozone or Walmart.  Or can I use the 50/50 mix that you see below?

So - what do I need?  Thank you!

Re: Which Antifreeze for Aqua Hot 431/12

Reply #1 –
Quote from: Steve & Kathy B –
I've search all over and I'm still not sure which antifreeze to use to top off my Aqua Hot antifreeze expansion tank. I have a Model 431/12, with serial #99978.

There's a sticker on the plastic tank that says to use a Texaco brand antifreeze.  That doesn't exist anymore.  George left me some 50/50 antifreeze (see attached pic) but told me that it was for the engine, not the AH.

I'm guessing just straight undiluted ethylene glycol antifreeze for a regular car engine that one can get at any Autozone or Walmart.  Or can I use the 50/50 mix that you see below?

So - what do I need?  Thank you!

My engine, generator and aquahot came with the Texaco which is not available. Here is a some equivalent products of which your 50/50 mix is one of them. If George said it is not for the Aquahot he may have changed to "Camco" http://www.camco.net/#
The selected media item is not currently available.Barry BEAM #16014
2003 U320 40' AGDS
Beamalarm, Foretravel technical help and specifications
"Whatever the mind can conceive and believe, it can achieve"

Re: Which Antifreeze for Aqua Hot 431/12

Reply #2 –
Steve,

Your unit uses regular antifreeze.  Any good brand cut 50/50 with distilled water will be fine.

Starting in 2003, Aqua Hot begin to manufacture units that needed GRAS (Generally Recognized As Safe) antifreeze which the Camco Boiler Antifreeze is the choice of Aqua Hot as they sell it.

Camco Boiler Antifreeze sold by the gallon needs to be cut 50/50 with distilled water to be ready to use.  Camco Boiler Antifreeze concentrate sold by the quart needs to be cut with two quarts of distilled water to be ready to use.

Pink RV antifreeze sold in most RV parts stores and Walmart is NOT boiler antifreeze and should not be used in the coolant tank of any Aqua Hot Heater.  It is used to winterize the fresh water system in the coach including the fresh water loop in the Aqua Hot Heater regardless of year of manufacture.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: Which Antifreeze for Aqua Hot 431/12

Reply #3 –
GRAS, Generally Regarded As Safe, is a description by the FDA for propylene glycol antifreeze and engine coolant.  Some RV plumbing system antifreeze is PG based but NOT suitable as an engine coolant.  One advantage of PG in this usage is that the constant heating cycles will produce less glycol degradation products.  Using ordinary EG engine coolants can produce some nasty products such as formic, glycolic, and acetic acids which will attack the metals in the system.  PG degrades to lactic acid which is much less aggressive. 

In the first post a picture of the sticker showed the system was filled with Texaco Extended Life (OAT) antifreeze/coolant.  If your systems are composed of soldered copper heat exchangers, that product will cause corrosion of the lead solder leading to leakage.  The same for Dexcool, Shell Rotella ELC, Chevron Delo ELC as all these products contain ethyl hexanoic (ethyl hexanoate).  Use any other engine coolant but not these particular OAT coolants with any soldered copper heat exchanger or radiator.
Gary Spires
Coolants, Cooling Systems, Filtration, Diesel Engines

Re: Which Antifreeze for Aqua Hot 431/12

Reply #4 –
There is lots and lots of confusion about which coolant is used in various models of Aqua-Hot heaters.  Generally speaking if your Aqua-Hot has electronic control board, then it should use the Camco –100 Boiler coolant or equal.  All older heaters, use 'standard' ethylene glycol (Prestone or equal).  If you have a question about your specific Aqua-Hot, email me your model number and serial number and I will let you know which coolant you should use.  There is also information on my website RV Hydronic Heating Repair - Hydronic Heater Model Information  that lists the different models and which type of coolant they should use.  As always, if there is a sticker on your unit stating which coolant to use, follow directions on that label (see attached photo).

Many of the Foretravel coaches use the Texaco ELC coolant in the engine.  To keep things simple they also filled the Aqua-Hot and the generator with the same coolant.

Your Aqua-Hot model 431 can be filled with any ethylene glycol based coolant.  I believe that the Fleetgard ES Optimax is an equal product to the Texaco ELC coolant.  Keep it simple and use the same coolant in your Aqua-Hot, engine and generator.

I am far from being a coolant expert, however many of our coaches have had Texaco ELC in the Aqua-Hot, some for almost 15 years.  I have not seen any evidence of any breakdown of soldered connections.

It is important that you do not mix the Camco -100 Boiler coolant (propylene glycol) with the Texaco ELC (ethylene glycol) coolant. 

- Roger Berke -

Re: Which Antifreeze for Aqua Hot 431/12

Reply #5 –
Roger,

"It is important that you do not mix the Camco -100 Boiler coolant (propylene glycol) with the Texaco ELC (ethylene glycol) coolant. "

Is your statement based on not mixing PG & EG or Camco inhibitor chemistry vs Texaco OAT chemistry?

Gary Spires
retired Fleetguard (Cummins) engineer
Gary Spires
Coolants, Cooling Systems, Filtration, Diesel Engines