I just installed a new water pump...on the coach--before I did the old pump did not pump the anti freeze very well so thought the pump was gone...the new one does't pump all that well...I have an 03 W...
You could be pumping the pink stuff into you water heater if your water heater bypass valve is not working correctly.
I agree with the post about using air. When I had our Winnebago, I never used the pink stuff... just drained all the water and used a compressor to blow out the system. Poured the pink stuff down the P traps and that was it. Never had a problem.
Now that I have a rig with Aqua Hot, it seems I must use the RV antifreeze for the Aqua Hot unit.