Pump Isomac Venus buzzes, but doesn't pump water

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by dileoni »

HI all,

a friend just recently bought a second haand isomac venus, it worked fine when we tested it at the place, but after transport the pump only softly buzzes but doesn't pump any water or makes a louder sound as it should. Anybody has any idea?

Kind regards



#2: Post by RobAnybody »

It could be there is some air in the pump, you can help priming it by opening the steam tap when the machine is trying to pump.
An other option is to use a syringe and push some water into the inflow line and then start then start the pump.
LMWDP #647


#3: Post by dileoni »

Hi Rob,

Thank you for your reply. We tried all options.No luck yet. We opened up the pump. The ball inside was stuck. This helped some, but, Now it makes some loud noise, but still doesn't pump any water. Maybe soak it in descaler for a bit?

Kind regards,



#4: Post by nahau »

I'm assuming your machine has an Ulka pump. If so, open up the pump again and check to see if the piston o-ring slides easily on the piston shaft. Also check if it's hardened... it should be soft like the rest of the orings on the pump. If it's hardened and can slide easily on the shaft, then it needs to be replaced. This o-ring is the main cause of low pressure in ulka pumps. The o-ring size is 5mm x 2mm, or 5/16" x 3/16".