Whirlpool issues

[sgraham602]

So I'm stumped! I have a pump that I use throughout the brewing process (recirc, sparge, transfers). However, when I reach the end of the boil...it will not whirlpool through by whirlpool inlet. I can whirlpool PBW while cleaning, but not wort at the end of the boil. I've tried all sorts of ways to make sure that the pump is being primed, so I'm almost certain that is not the issue. I'm wondering if its the heat thats causing the issue?

 

[BargainFittings]

Are you getting any transfer at all? Or you don't see a swirling motion?

 

[IslandLizard]

Do you have a filter screen in there? Hops can clog that quickly and more so when pumping, starving the pump.

 

[sgraham602]

Pump works fine during transfer (pre boil), post boil I let it gravity feed.

I use a hop spider, so I have very little hop matter getting into the pump.

 

[Auger]

Is the pump turning, just not pushing any hot wort?

The pump may be cavitating as soon as you turn it on, so even if inlet and outlet lines are primed, if the pump head cavitates enough it will lose prime and not push any liquid. I have this problem with mine. With near-boiling liquid, just the initial push of turning the pump on can cause cavitation, which will cause the surrounding liquid to boil due to the reduced pressure caused by cavitation. What I have to do is close the ball valve on the return line, start the pump, then slowly open it to get hot wort recirculating. As the wort cools, I can open it more. If I open it too fast, the pump impeller cavitates, all liquid recirc stops, I have to turn off the pump, close the valve, and start up the pump again.

 

[sgraham602]

Is the pump turning, just not pushing any hot wort?

The pump may be cavitating as soon as you turn it on, so even if inlet and outlet lines are primed, if the pump head cavitates enough it will lose prime and not push any liquid. I have this problem with mine. With near-boiling liquid, just the initial push of turning the pump on can cause cavitation, which will cause the surrounding liquid to boil due to the reduced pressure caused by cavitation. What I have to do is close the ball valve on the return line, start the pump, then slowly open it to get hot wort recirculating. As the wort cools, I can open it more. If I open it too fast, the pump impeller cavitates, all liquid recirc stops, I have to turn off the pump, close the valve, and start up the pump again.

That might be the trick. The pump is turning, but not pushing any wort. Every time i open the valve there is a bubble of liquid from the kettle, but then it stops. I bet what you described above is what's happening. I'll try slowly opening the valve next time.

 

[heckels]

I've had the same issue. I typically try to recirc the last 10 mins or so of my boil and had thought maybe air bubbles from the boil was causing issues. But after the boil when trying to whurlpool I have the same issue.

I'll give this a try the next time and see what happens.

 

[brick_haus]

Auger,s solution is the correct one. Keep the pressure on the discharge side of the pump with hot liquids to reduce cavitation.