Aqua Hot

[Keith Moffett Co-Admin]

re; AHE 100 04S

Has anyone here completely drained and installed new boiler fluid in their system?  I seem to recall this should be done every couple years.
Ours has a mix of colors resulting in murky colored fluid.
We lost two heat exchangers last year and I am concerned the new fluid might cause the rest to go.

Anyone have a fill capacity for the radiator in the AH?

Thanks

[Bill Lampkin]

Flushing the System
Aqua-Hot does not recommend draining and flushing the system unless the wrong type of fluids were added to the boiler fluid.
For example, if your system uses propylene glycol “GRAS” antifreeze, but ethylene glycol was mistakenly added, the system would need to be flushed for safety reasons.

http://www.aquahot.com/faqs.aspx#antifreezeflushing

Lots of info on AH website. I have same unit as yours, and I bought a refractometer last year to check on the fluid concentration. The test was simple and indicated my AH fluid was right in range. Ours is 2005 and AFAIK the fluid has never been changed.

All the best

[Bill Lampkin]

Keith, I looked it up-boiler capacity is 16 gal of 50/50 mix of water and boiler fluid. Got lotsa milk jugs?

[Bill Lampkin]

Installation manual pg 50-52

http://www.aquahot.com/files/installation_manual/AHE-100-04S_and_130-04X_Installation_Manual_07-05.pdf

[Eric Maclean Co-Admin]

Hi Keith
 you say you lost two heat exchangers last year I personally would be checking the fluid with test strips for acidity
I have an aquahot in my 23 year old coach and although it is the older style which doesn't require no toxic boiler antifreeze  I did have a rust issue and had to rebuild the boiler even so I am still using the original heat exchange radiators ( knock on wood).
The other thing to check might be the pressure ( rad cap) on the boiler for it's release pressure and vacuum valving.
I believe aquahot recommends frequent replacement of the cap .
An over pressure or pressure and vacuum cycling me be causing your heat exchanger failures.
Good luck
Eric

[Keith Moffett Co-Admin]

Thanks Bill
I have figured out that while I have become competant at the basic work on these things I have had three different versions and the  requirements get mixed up.  Funny that that info should be in the 'Installation ' manual as opposed to the service manual.  In any case it would cost over $300. to drain and fill the system so if it isnt reccomended then I will think on it a little more.   One heat exchanger that went out is under the kitchen cabinet and you have to crawl in through a drawer opening.  When that is done it may make up my mind for me ...

Eric,
So what you are telling me is that the new cap I put on just before losing the first heat exchanger might be the problem?  I hate it when that happens!  Wouldn't surprise me though LOL!
Will try the acid test hopefully before one of the tougher ones goes out. 

[Larry Dedrick]

Keith
           If you do elect to go with a fluid replacement, keep in mind that a final flush is to be accomplished with distilled water.
Made sure the tech that did ours knew this.

[Eric Maclean Co-Admin]

Keith any automotive repair facility should have a pressure tester for radiators which with the proper adapter can be used to check the new rad cap for it's release pressure.
Check with aquahot for the specification for the cap.
Eric