At this point in my research my view is that this anti-freeze business is just propaganda from the service operations and the guys that sell anti-freeze. The fact that the Alde system should not be subject to this makes the process of using the anti-freeze much more complex and difficult to understand, and if the simple air pressure purging approach is suitable for this major segment of the system, why should it not be entirely adequate for the rest of the system?
Reading between the lines it seems apparent that there has been dissension between the Alde and T@B technical and marketing people. Why is Alde so staunchly opposed to anti-freeze? My guess is that winter operation with no hot water function requires that the hot water tank be air filled and preferably vented, and the presence of any liquid, which would expand and contract significantly as the system cycled from inactive with temperatures possibly far below zero to relatively hot as the glycol was heated, mechanically stressing the system, especially if it was relatively full of anti-freeze.
T@B technical and marketing people seem to be between a rock and a hard place, the anti-freeze fad has a lot of push behind it and the Alde people will not bend on warranty issues and believe that their credibility and reputation would suffer from anti-freeze related failures. So T@B has been backed into a corner and introduced this complex and unnecessary system of by-pass valves, and no end of user confusion and doubt.
There is of course a strong element of speculation here, it will be most interesting to read other views and opinions.
Perhaps someone will come forward and explain exactly how the use of anti freeze is beneficial.
Comments
The by-pass valves are used when sanitizing the system - you don't want bleach in your Alde hot water tank. It can corrode and weaken the stainless steel.
Personally I agree with you - the blowout method is so much easier, both winterizing and de-winterizing. I don't have to mess with cleaning out the antifreeze from the lines in the spring!
OK, good to know about the bleach, will make note of it.
The frustrating part of all of this is that there are so many direct and indirect conflicts between statements by various venders, and indeed by the same vender in different places, sometimes in the same document.
SO, I guess my experience says circulate some antifreeze and then blow the system as clear as possible for the best possibility of avoiding problems .
I rely on the blowout method only. However, I am confident enough in both my knowledge of plumbing and my skills so that I don't feel the need for such a policy. I can certainly understand why someone else might prefer the peace of mind that comes with using antifreeze, despite the extra work and expense.
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