Any thoughts on this HX issue

[simonko Senior Member Find all posts View Profile Close simonko]

Back from 2 week holiday and the Bezzera (BZ99) is suddenly playing up. Pretty standard inside so same theory should apply to many basic HXs.

Heats up ok, maintains temp with heating cycles so pressostat seems to turn on and off ok. Can pour a shot after heating up ok (vibe pump seems good), but after about 25 minutes of the machine being on, the relay opens. Then I can no longer pull a shot and the boiler no longer heats.

Only inputs to GICAR are boiler min level, boiler max level and tank level. I can't see it being the inputs.

Is this a symptom of a GICAR on the way out? Any other thoughts?

[brendanw Member Find all posts View Profile Close brendanw]

If it comes back to life after cooling down it could be the thermal cut-out kicking in (if you have one of the newer models with this, it's designed to kick in at 115c and kill the power). So your pressure-stat might not be working correctly and letting it heat up too much.

[Chrisj1984 Member Find all posts View Profile Close Chrisj1984]

Hi there, i have the same machine. Site sponsor the coffee machinist may have some suggestions. He is in melbourne and Was great with my machine. Maybe send him an email.

[simonko Senior Member Find all posts View Profile Close simonko]

If it comes back to life after cooling down it could be the thermal cut-out kicking in (if you have one of the newer models with this, it's designed to kick in at 115c and kill the power). So your pressure-stat might not be working correctly and letting it heat up too much.

Good point, however my boiler doesn't have the thermal protection. Also I think if a cut-out was on my model, it would just prevent the boiler element getting power while still allowing the shot to be pulled, right?

[simonko Senior Member Find all posts View Profile Close simonko]

Hi there, i have the same machine. Site sponsor the coffee machinist may have some suggestions. He is in melbourne and Was great with my machine. Maybe send him an email.

Thanks - being in outer-Sydney I wouldn't be able to somehow use the sponsor's services and don't feel right asking from free advice from someone in the business.

[brendanw Member Find all posts View Profile Close brendanw]

Good point, however my boiler doesn't have the thermal protection. Also I think if a cut-out was on my model, it would just prevent the boiler element getting power while still allowing the shot to be pulled, right?

You are right there it should only kill the element power (always a little difficult trying to diagnose faults just from words). I would have a look at the two tank sensor wires then and make sure they are in good condition and the connections are clean. Could also be a capacitor or transformer in the Gicar on the way out (most likely to be affected by heat), the capacitor will usually bulge. The Gicars are electrically very simple so if you know what you are doing they are easy to repair. If you don't know what you are doing then you shouldn't be inside the machine and should take it to a service centre, you can't enjoy your coffee machine when you are dead.

[simonko Senior Member Find all posts View Profile Close simonko]

You are right there it should only kill the element power (always a little difficult trying to diagnose faults just from words). I would have a look at the two tank sensor wires then and make sure they are in good condition and the connections are clean. Could also be a capacitor or transformer in the Gicar on the way out (most likely to be affected by heat), the capacitor will usually bulge. The Gicars are electrically very simple so if you know what you are doing they are easy to repair. If you don't know what you are doing then you shouldn't be inside the machine and should take it to a service centre, you can't enjoy your coffee machine when you are dead.

Thanks, we seem to be thinking the same thing on the Gicar.

I'll do a proper investigation - more wondering if this symptoms were common in order to save some time.

[simonko Senior Member Find all posts View Profile Close simonko]

Finally got desperate enough to get my machine fully functional again - replaced the Gicar with one from a spare machine I have and it did solve the problem, in case someone encounters similar symptoms.

A quick look inside the faulty Gicar showed no obvious bulging caps or burns. No time to diagnose the issue - which I'm sure I'll regret when the working Gicar karks it.