I just replaced the pump in my Alexia. The old one was stuttering, then turning off for longer stretches during shots.

The new pump has also stuttered a few times, making a sound like an electric buzzer. I had run water though the group when it was cold and it seemed to work fine. It worked fine for a couple of shots too, though the old pump's problems were intermittent.

Has anyone experienced buzzing / stuttering with a new pump? Do you think it's OK to use the machine and watch, or am I at risk for breaking something else?

Anything I should check? When I ordered the pump I asked the tech at the shop if the PID might be part of the problem, he said it wouldn't.

Thanks.

That "sounds" as though there is something amiss with the brew switch on the front of the machine. With the machine UNPLUGGED from the wall socket, check the switch connections for tightness and check that there is still only about 1/32" of free play in the switch's push button when the lever is in the brew position.

Thank you Eric, I'll take a look at those connections and the button tonight.

Phil

Thanks again Eric, I checked the switch connections twice (best I could) and they seem secure.

I also checked the mushroom (Thanks Eric) and found a bit of what I assume is scale on the mushroom, chamber looked clean. Not built up and it's been 3 years of use, but I didn't expect any.

Very long question short - is there any reason to think scale might be causing a stuttering pump problem?

If this were a problem caused by scale is it reasonable to think a cleancaf type descale might be strong enough to help?

Thanks.

Now this is a long shot BUT . . . the pump is very likely equipped with a thermal diode (opens on high coil temp) pocketed visibly in a recess on the top of the pump. With the machine UNPLUGGED, temporarily remove this diode from the circuit and reconnect the pump's electricals.

I would not apply any descale solution.

Thank you Eric. I'll give it a try.

Fixed, I think.

Thanks Eric for all of your help.

Before my last post, I had more than a page of questions and ideas which I whittled down, I should have
left:

Seems to happen when the reservoir is half full

I checked. When the tank was low the pump stuttered, when I tilted the tank to get the magnet closer to the sensor, stuttering stopped. I replaced the float and so far it seems to be working normally.

Thanks again,
Phil