chris wrote:What makes no sense is why the steam boiler pressure would drop as a result of doing a cooling flush?

Wouldn't the boiler pressure drop while doing a cooling flush or while pulling shots since bringing in cool water through the HX which then cools the boiler? Of course should only drop pressure to regular pstat toggle low point, then come back up to regular pstat toggle high point. Definitely should not have reducing or wildly varying pressure overall because of flush or shots or steaming.

You're in good hands with Chris' Coffee. Another possibility is scale buildup; that would explain the low brew temperature.

A little follow:

This thread got derailed before really getting started because the term "cooling flush" was erroneously used. There was no cooling flush. Forget about it. There was a steam purge and/or partial boiler flush.

The problem was caused by a sticking vacuum breaker.

It can be diagnosed by letting the machine heat up, and briefly opening the steam valve. If the boiler pressure gauge drops to zero -- it's sticking in the "up" position. So, I learned from a phone call to Roger, the La Cimbali tech at Chris Coffee.

I solved the same problem with my Casa -- at least temporarily -- by opening the machine and freeing the pin on top of the vacuum breaker by pushing it in. I'm not sure if this is a temporary fix which will hold indefinitely, or I'll need to remove the old breaker and lube the pin, or replace the entire part.

My understanding is that since starting this thread Derek (aka tomesd, the OP) R and Rd the vacuum breaker in his machine which took care of his problem for awhile, but his machine is back to the same stupid trick. Derek's experience doesn't fill me with confidence, but we'll see.

BDL

Rich,

No need to replace the vacuum breaker as it can be broken down and the O-ring replaced. I did that on mine and had to lube the O-ring to keep it from sticking. I used Dow 111, and so far, so good.

Good to know. Do you remember what size O ring?

BDL

O-rings & Copper Sealing Washers

Contact me if you would like some.

Thanks Eric. Will do. So far -- after one whole day -- the "repair' is holding.

BDL

A bit more follow up:
After one week following the expedient "repair" of freeing the pin, the vacuum breaker is still working as it should. So, no new o-rings, lubrication or partial rebuilds for now.

As to the rest of it... my love affair with the Casa continues.
BDL