Stormin Mormon wrote:

I'm sure I've wasted a lot. Yes, you did mention to bypass the water heater.
Sadly, the two I've done so far, no sign of a bypass valve. A friend of mine
comments "these must be older models". I'm sure they are. I will probably
use a lot more pink, in that case.

If you aren't draining the water heater and are only using 2 gal of AF
you aren't doing the job properly. The WH is going to be at least 5gal
capacity so without bypassing it will require at least 5gal of AF to
fill.

Again you do not need to leave the system completely full of AF either,
just ensure that any remaining liquid in the system is AF.

The proper efficient procedure would be:

- Turn off and disconnect the water supply
- Drain the system from the low point drains (open high point faucets to
let air in, a gallon or two should come out the drains)
- Drain the water heater (5 gal min should come out)
- Close the faucets and WH drain
- Use compressed air for ~1hr to blow remaining water out the low point
drains
- Pump AF into the system until it's flowing from the low point drains
(bucket there to catch it)
- Drain from the low point drains into the collection bucket
- Drain the WH into the collection bucket
- Close up the system
- Pour a cup or two of AF into each toilet or drain trap

This should leave only AF remaining in any low points in the system and
things properly winterized without leaving everything full of expensive
AF. Blowing all the water out first ensured you are diluting the AF as
little as possible so it is readily reusable on the next trailer.

The key thing to remember is that you do not have to have everything
full of AF to winterize it, you only have to replace any water that
can't be readily drained with AF, i.e. any low points in the plumbing.
Presuming small water heaters and not many low points in the plumbing
you should need perhaps 6-8 gal of AF overall to do all the trailers.