View Full Version : Air bubble in glycol lines?

04-30-2009, 12:21 PM

I have two open topped 10bbl fermenters cooled by a closed loop glycol line. There are two 3/4 hp pumps which move the glycol. Normally if an air bubble pops up somewhere, I can open the release valve and it would find its way out.

Right now, my glycol lines are "breathing" air is being sucked in from somewhere and then expelled. I have never seen this before. The glycol cannot move because it gets pushed a little, then pulled back a little.

Any suggestions?

Patrick Fiori
Clocktower Brewpub

04-30-2009, 12:50 PM
Have you checked the reservoir? Something similar happened to me, and it was because there was a small glycol leak in one of the lines. Eventually the pump started sucking air.

05-01-2009, 04:19 AM
Check pump inlet/connections. Also check pump face for leaks (turn it off and watch it). Check glycol reservoir outlet (pump feed) to ensure it is not blocked.

You may have a blockage somewhere in your glycol loop. Can you drain the glycol and check flow with city water through the lines?

Good luck.



05-01-2009, 08:43 AM
In addition to Liam's suggestions, if the problem has only recently shown up, you may have a slowly failing seal on the glycol pump... leaking seals can manifest as liquid leaks or as air being pulled into the system, depending on the system dynamics - often the seal area is under a slight vacuum and a leak will pull in air.

Hope this helps