La Marzocco Linea making weird noises when filling steam boiler

#1: Post by **mitch236** » November 30th, 2011, 9:13 am

A few weeks ago, my Linea's pump froze and while I was waiting for the replacement, I unfroze the pump manually and used it for a few days. Since then, I've noticed a louder, buzzing-almost grinding noise whenever the steam boiler fills. The steam boiler works normally (fills when needed and the water level is correct) so the water is getting through. The brewing side of the machine works and sounds normal.

I was thinking the three way valve for the steam boiler got some piece of debris caught when I unfroze the original pump. Does that make sense? Has anyone else had this problem? I'd hate to spend money chasing this and calling a tech would be expensive too. Plus, I'm a hands on guy and enjoy fixing my own machines.

November 30th, 2011, 9:42 am

Also, does anyone know offhand if the 3-way valve for brewing is the same part as the valve for the steam boiler? (I have the old 3-way valve from my Piero cap mod still laying around)

#3: Post by HB » November 30th, 2011, 10:17 am

What diameter is the input line (3/8")? Are their filters or pressure regulators? I ask because if there's a flow restriction, the pump can cavitate. It's an awful squeal/grinding sound. A quick check is to draw water directly from a jug (note: the pump does not require positive pressure).

November 30th, 2011, 10:27 am

I'm very sure it isn't the water supply. When the pump activates for brewing, there is no issue. It's only apparent when the steam boiler is filling and the sound eminates from the right side of the machine. The pump is below the machine in the cabinet.

#5: Post by **NickA** » November 30th, 2011, 7:01 pm

Hi Mitch, the solenoid for the steam boiler will be a 2 way solenoid because it just has to turn flow on or off, not vent pressure as the three- way brewing one does. If you were to cap the 3rd outlet, you could probably use it for the steam fill. About the only other thing in line from the pump to the steam boiler is the non-return valve, which you could check for dirt, but I would have thought it's not all that likely to be making the noise.

#6: Post by **Paul_Pratt** » November 30th, 2011, 9:37 pm

It's a 3-way on the steam boiler fill as well, capped off on one port. It's also placed with the arrow against the flow to prevent any high pressures filling the steam boiler accidently. So yes you can use the old solenoids from your boiler.

It could be some debris or just a pipe rattling. Also inspect the check valve after the solenoid as well.

There is always a bit of a rattle anyway but if it's louder than before then you should investigate.

Paul

December 1st, 2011, 10:42 am

Thanks Paul. EPNW is out of the two way so I'm happy I can use the old 3-way.

Weekend project!!