Hey Everyone.

My vibe pump seems like it's on it's last legs, but I'm not sure how to tell if it's the pump or if it's something that contributes to creating the pressure.

It starts strong with no pressure, once the line pressurizes it SOMETIMES goes to complete silence, not even a low hum - which I've experienced before.

Oddly - to me, anyway - is that pressure still remains quite high in-line and the shot will continue to pull.

So, why does my vibe pump go silent? You'd think this was a God send, but... I know it's something about 10000000000000x worse than that.... although if it's a pump failing... that's not HALF bad..

What I've found on 3 Ulka pumps is that they exhibit this behavior after a couple of years when they get hot AND the water in the reservoir is quite warm

My office machine only does it late in the day with the steam boiler on and the home machine only on Saturday afternoons. Other than that they are flawless.

Try putting some cool water in the reservoir and see if that helps.

hmmmmm it does happen still... I don't get it... is it 'tired'?

Question is - If it continues to pull even when it goes almost completely quiet, should I care? The pressure doesn't seem to ease up considering the shot times are similar to prior normal operation pulls with the same beans and parameters.

I think I should just get a new pump, but I'm not 100% convinced that IT IS the pump. Is it? I've opened up the machine and see no in-line leaks - I've experienced the leaks from the flowmeter before which gave a similar experience - it's just seemingly the pump acting up.

Pressure drops to about 6-8bar gauge, about 5-7 puck when failing. Flow remains about the same, but taste flattens

When it's happening remove the machine sides and blow some cool air across the pump.
If you have an IR thermometer, measure before and after.
Mine failed about 130°F and performed @ 110°F

Note that the sticker on the Ulka specs Max water 25°C
Reservoir water temp was about 45°C / 110°F.
When I added room temp water, no problem.

So is it getting too hot inside the encasement? When I add water it's from the fridge and quite cold, actually. I'll see what I can do... I don't have an IR thermometer and also, it's not a good situation if this is going to be normal procedure going forward...

This same problem has come up before - try doing a search on "quiet Anita" or "quiet Ulka" or similar terms.

I BELIEVE the cause is a "stuck" suction check valve internal to the pump - see the item in red below - a small sphere ~ 1/8" in diameter. I have experienced the problem that Ian is writing about on Quickmill machines when the reservoir is unusually low and the OPV is discharging hot water back to same. This is easily cured by filling the reservoir with water.



This small ball is, I believe, plastic and may be replaceable (with glass?) depending upon your luck in scouring the internet for "glass balls" and your willingness to disassemble the pump.