keeping the wort pump primed seems to have a learning curve

Question

So, I bought myself a pump and a chillizilla-type chiller and a chugger pump for christmas...thanks for the christmas bonus, Boss...also, silicone tubing and stainless fittings and such to make it work.

After I had everything plumbed in the basement to make sure that things were where they needed to be, I could run the pump full bore and get LOTS of water coming thru the outlet tube back into the pot. All was well, I thought.

Yesterday, when I brewed with the new toys for the first time, I had to throttle the flow back to a trickle to keep from losing my prime coming out of the kettle.

After I got done, I cleaned the system and ran PBW thru it again and it was back to running full stream.

So is the problem the sugar water being thicker than water or the heat? Or is there something else I'm missing?

Answer 1

While sugar solution is thicker than water, it's only by 4-10% for a typical brew, so I doubt that is your problem. It's more likely a partial blockage or a connection that is letting in air.

One other thing that can cause a reduced flow - it's important to get all air out of the tubes that run from the kettle into the pump. I have the pump placed below the kettles so that the liquid will naturally run down and fill up the pump, displacing the air. Rocking the pump a little can also dislodge any stuck air bubbles in the pump head, since they will naturally want to rise up and out of the outlet. For this reason, it's best to have the flow through the pump going continually upwards, so air bubbles can easily escape.

If you get any air bubbles, restrict flow on the out side of the pump, and gently squeeze the inlet hose, this is usually sufficient to coax them out into the hose. Then slowly open the valve again up to full flow.