My vac can run and was running 26-27" but the hobby releasers are what they are and won't work very well over 24" the check vavlve won't release and with that much vac pressure. so it kept backing up besides boiling tuesday I boiled off 275 gallons and only got about 2.5 gallons which is alot of wood and alot of time. If I had and RO no problem I probably would have kept on going. but still by tuesday lunch I managed 20 gallons, and with being warm you really just can't hold it for very long because its already starting to ferment in the tubing!!! Anyway!!! Can't controll the weather right...not yet anyway...I just finished out everything and took some nice pics that you might see in the union leader's story for the maple weekend I had a woman contact me so hopefully it will get in there. Good luck finishing the season...Brad