# Cherub keeps getting airlocked



## Edward (Sep 21, 2010)

Hi folks

I keep having an issue with my cherub whereby I need to release air from the steam wand before the boiler can pressurise.

The group seems to be already hot before I do this, so hot water is circulating, there's just no steam pressure.

The machine comes on with a timer, I come to it about an hour later and the pressure needle will be at one bar. I open the steam tap, air comes out, pressure needle drops and the boiler kicks in to build up proper pressure.

Any thoughts?


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## coffeebean (Jan 26, 2010)

Sounds perfectly normal, if you were there when it was warming up you would open the steam valve until it started to steam and then close it which would release any air locks. The fact that it is warming up on its own with the steam valve closed means that the air has nowhere to go until you arrive and let it out.


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## DavecUK (Aug 6, 2013)

Edward said:


> Hi folks
> 
> I keep having an issue with my cherub whereby I need to release air from the steam wand before the boiler can pressurise.
> 
> ...


your vacuum breaker is sticking closed sometimes by the sound of it. The whole point of the vacuum breaker is to release false pressure.

http://coffeetime.wikidot.com/vacuum-breaker

Sometimes you can clean them temporarily, but getting the machine up to full pressure and using a wooden stick, press in the Vac breaker and the steam rushing out can sometimes ungum the seal. Usually though removal and cleaning are required. if the machine is old (7+ years), getting a new one can help, they are a standard and inexpensive part.

P.S. Although the group might seem hot it won't be as hot as it should be and you will need to release that false pressure and leave it for 10 minutes before you make coffee. if you don't any extractions will be under temp.


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## Edward (Sep 21, 2010)

DavecUK said:


> your vacuum breaker is sticking closed sometimes by the sound of it. The whole point of the vacuum breaker is to release false pressure.
> 
> http://coffeetime.wikidot.com/vacuum-breaker
> 
> ...


Excellent, this is very informative.

I'll have a look. I'm not the most handy sort so I may need to pay a fracino repair technician to do this.

The machine is about nine years old, so it wouldn't surprise me if it just needs a new vacuum breaker.

Thanks a million


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## DavecUK (Aug 6, 2013)

Edward said:


> Excellent, this is very informative.
> 
> I'll have a look. I'm not the most handy sort so I may need to pay a fracino repair technician to do this.
> 
> ...


You don't need a repair tech, just a 14 or 16mm socket, a hammer for some tapping to free it (impact type tapping, not tapping on the vacuum breaker itself, but on the socket handle), PTFE tape to fit the new one instead of threadcocker. It's a 15 minute job, it will take you longer to pack it. if they didn't use threadcocker, it would be a 5 minute job and no trouble undoing it.


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