# Pressure "cycling" normal on HX machines?



## Edward (Sep 21, 2010)

Hi guys,

It seems on my fracino cherub the pressure goes in "cycles" where it reaches 1 bar then slowly drops down to .5 or so over 30 seconds, then the element kicks in and it raises to 1 bar again.

Is this normal?

See video here for a closer look (please ignore the sound its the missus playing fable 2 in the background, I dont have a collection of odd sounding slaves, I promise)






If it has any effect at all the kitchen window nearby is open a crack and theres only 3 cups on the cupholder if that affects heat leeching.


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## LeeWardle (Nov 16, 2008)

Wow! Scary noises!

It shouldn't normally drop down that low. If it has a pressure switch you can just adjust .it to make the element kick in at a little earlier or if not it will have a little thermostat. That is probably a bit duff and will need replacing. Fracino have a really good after sales department. Give them a call and they will advice.









Lee


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## Edward (Sep 21, 2010)

I just had another look at the gauge, when I said .5 bar I was wrong, it drops to about .7 each time from the looks of things. Do you think a part is faulty? or maybe just incorrectly set?

I had a look at the fracino parts diagram at http://www.fracino.com/uploads/CHERUB%20SPARE%20PARTS%20MANUAL%202008.pdf

it looks like it has both a pressure switch and a "high limit thermostat".

I'm not very comfortable modifying things though, so if the machine is set incorrectly, I'll probably need to return it?


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## BanishInstant (Oct 12, 2009)

I have a Gaggia HX and I've not seen such a drop and rebound. As Lee suggests, give Fracino a call for some advice, but I think it may need returning if under warranty


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## LeeWardle (Nov 16, 2008)

Ok then thats not too bad. The pressure switch may need slight adjustment. HOwever, I don't suppose the guage is "NASA" accurate! A quick call to the guys at Fracino will let you know if you need to worry. They will be more than happy to advise you.

A slight drop is quite normal however.

Good luck and keep us informed!

Lee


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## Omaristalis (Sep 29, 2010)

My Epoca cycles up to 1.3 and down to 1, and that was with a brand new Sirai pressurestat. A .3 bar deadband on these things is normal, I think.

I salvaged a PID temperature controller from a skip with some thermocouples, so I am thinking of PID'ing my boiler, which I suspect is the only good way to improve the deadband.


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## RisingPower (Dec 27, 2009)

Same thing happened on the izzo, time to buy a new pressurestat. Or in this case a "pressure switch".

Worse on the izzo, it didn't shut off sometimes at all. Deadband is typically ~.2 bar on the izzo, or cycling for maybe a few seconds.

Was very easy to replace on the izzo, from the looks of the diagram shouldn't be too hard on the fracino. One thing to bear in mind, keep an eye on the pressure gauge and have access to the pressure stat whilst the boiler heats up for the first time.


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