Post By deegee
Ulka ex5 making bad noise
I've got an expobar office that I just finished reconditioning (fully stripped and rebuilt). I got the machine back together and running. I put the blind filter in and pressure tested to check for leaks. After about 4 cycles on and off, the water pump started to make a horrible sound, and it stopped heating. It still pumps, but when it's operating it sounds similar to a loud electrical buzz. I've tried 3 different pumps and they all make the same noise. If I put the pumps onto another machine, they sound fine.
Does anyone have any ideas? I'm lead to think there's some sort of electrical fault, but if anyone has any ideas that would be really helpful.
Vibe pumps will make different sounds depending on the situation. If there is little or no water available to the pump they sound louder and make a harsh metallic rattling buzz. When pumping against high pressure e.g. when the shot is choking, the sound is usually a fairly quiet hum/buzz.
When pumping against a normal resistance, e.g. a good grind/dose/tamp, the sound is in between these two extremes.
I'm not sure from your description of the sound, but it seems likely that you have a blockage. If the sound is louder and harsher than normal, it is restricting water getting to the pump. If the pump sounds quieter than normal, then the blockage is probably downstream from the pump.
Yep, will be some other part of your machine that's the problem for sure. A blockage in a valve or group head is probably the most likely cause. Might be time to take it into a technician for a look.
Originally Posted by Gemptron
Autofill is probably calling for water and not getting any resulting in the boiler to overheat and trip the thermal cutout. That would explain the no heating.
This is probably happening as the pump isn't pumping water anymore. As Deegee said, a loud buzz is the pump working dry and not pumping water. The EX5 can sometimes become airlocked even though they should be self priming. A good way to see if this is all the problem is is to apply some positive pressure to the water inlet hose to the pump whilst it's on and see if it sucks some water in. To do this, either blow into the hose or get a syringe to pump the water in.
If the pump suddenly goes quiet, that means it has primed. Switch the machine off as soon as this happens. Put the inlet hose back into the water tank and turn the machine back on, hopefully it should work as normal and all you need to do is reset the thermal cutout on the boiler. If the pump loses prime again, it will probably need to be replaced.
I'm not sure why 3 different pumps have had this same problem though. Have you checked the water inlet hose from the water tank for any kinks or blockages? The hose isn't sucking itself onto the bottom of the water tank is it?